diff --git a/dart/example/example.dart b/dart/example/example.dart
index 5b7cccc8781..c84ffa60198 100644
--- a/dart/example/example.dart
+++ b/dart/example/example.dart
@@ -123,26 +123,24 @@ bool verify(List<int> buffer) {
 
   // Get and test a field of the FlatBuffer's `struct`.
   var pos = monster.pos!;
-  assert(pos != null);
   assert(pos.z == 3.0);
 
   // Get a test an element from the `inventory` FlatBuffer's `vector`.
-  var inv = monster.inventory;
-  assert(inv != null);
+  var inv = monster.inventory!;
   assert(inv.length == 10);
   assert(inv[9] == 9);
 
   // Get and test the `weapons` FlatBuffers's `vector`.
   var expected_weapon_names = ["Sword", "Axe"];
   var expected_weapon_damages = [3, 5];
-  var weps = monster.weapons;
+  var weps = monster.weapons!;
   for (int i = 0; i < weps.length; i++) {
-    assert(weps[i]!.name == expected_weapon_names[i]);
-    assert(weps[i]!.damage == expected_weapon_damages[i]);
+    assert(weps[i].name == expected_weapon_names[i]);
+    assert(weps[i].damage == expected_weapon_damages[i]);
   }
 
   // Get and test the `Equipment` union (`equipped` field).
-  assert(monster.equippedType.value == myGame.EquipmentTypeId.Weapon.value);
+  assert(monster.equippedType!.value == myGame.EquipmentTypeId.Weapon.value);
   assert(monster.equippedType == myGame.EquipmentTypeId.Weapon);
 
   assert(monster.equipped is myGame.Weapon);
diff --git a/dart/example/monster_my_game.sample_generated.dart b/dart/example/monster_my_game.sample_generated.dart
index ced9b31b9ae..4f08860fb38 100644
--- a/dart/example/monster_my_game.sample_generated.dart
+++ b/dart/example/monster_my_game.sample_generated.dart
@@ -1,5 +1,5 @@
 // automatically generated by the FlatBuffers compiler, do not modify
-// ignore_for_file: unused_import, unused_field, unused_local_variable
+// ignore_for_file: unused_import, unused_field, unused_element, unused_local_variable
 
 library my_game.sample;
 
@@ -12,13 +12,16 @@ class Color {
   const Color._(this.value);
 
   factory Color.fromValue(int value) {
-    if (value == null) value = 0;
-    if (!values.containsKey(value)) {
+    final result = values[value];
+    if (result == null) {
       throw new StateError('Invalid value $value for bit flag enum Color');
     }
-    return values[value];
+    return result;
   }
 
+  static Color? _createOrNull(int? value) => 
+      value == null ? null : Color.fromValue(value);
+
   static const int minValue = 0;
   static const int maxValue = 2;
   static bool containsValue(int value) => values.containsKey(value);
@@ -26,7 +29,10 @@ class Color {
   static const Color Red = const Color._(0);
   static const Color Green = const Color._(1);
   static const Color Blue = const Color._(2);
-  static const Map<int,Color> values = {0: Red,1: Green,2: Blue,};
+  static const Map<int, Color> values = {
+    0: Red,
+    1: Green,
+    2: Blue};
 
   static const fb.Reader<Color> reader = const _ColorReader();
 
@@ -52,20 +58,25 @@ class EquipmentTypeId {
   const EquipmentTypeId._(this.value);
 
   factory EquipmentTypeId.fromValue(int value) {
-    if (value == null) value = 0;
-    if (!values.containsKey(value)) {
+    final result = values[value];
+    if (result == null) {
       throw new StateError('Invalid value $value for bit flag enum EquipmentTypeId');
     }
-    return values[value];
+    return result;
   }
 
+  static EquipmentTypeId? _createOrNull(int? value) => 
+      value == null ? null : EquipmentTypeId.fromValue(value);
+
   static const int minValue = 0;
   static const int maxValue = 1;
   static bool containsValue(int value) => values.containsKey(value);
 
   static const EquipmentTypeId NONE = const EquipmentTypeId._(0);
   static const EquipmentTypeId Weapon = const EquipmentTypeId._(1);
-  static const Map<int,EquipmentTypeId> values = {0: NONE,1: Weapon,};
+  static const Map<int, EquipmentTypeId> values = {
+    0: NONE,
+    1: Weapon};
 
   static const fb.Reader<EquipmentTypeId> reader = const _EquipmentTypeIdReader();
 
@@ -116,9 +127,7 @@ class _Vec3Reader extends fb.StructReader<Vec3> {
 }
 
 class Vec3Builder {
-  Vec3Builder(this.fbBuilder) {
-    assert(fbBuilder != null);
-  }
+  Vec3Builder(this.fbBuilder) {}
 
   final fb.Builder fbBuilder;
 
@@ -137,9 +146,9 @@ class Vec3ObjectBuilder extends fb.ObjectBuilder {
   final double _z;
 
   Vec3ObjectBuilder({
-    double x,
-    double y,
-    double z,
+    required double x,
+    required double y,
+    required double z,
   })
       : _x = x,
         _y = y,
@@ -147,10 +156,7 @@ class Vec3ObjectBuilder extends fb.ObjectBuilder {
 
   /// Finish building, and store into the [fbBuilder].
   @override
-  int finish(
-    fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-
+  int finish(fb.Builder fbBuilder) {
     fbBuilder.putFloat32(_z);
     fbBuilder.putFloat32(_y);
     fbBuilder.putFloat32(_x);
@@ -159,7 +165,7 @@ class Vec3ObjectBuilder extends fb.ObjectBuilder {
 
   /// Convenience method to serialize to byte list.
   @override
-  Uint8List toBytes([String fileIdentifier]) {
+  Uint8List toBytes([String? fileIdentifier]) {
     fb.Builder fbBuilder = new fb.Builder();
     int offset = finish(fbBuilder);
     return fbBuilder.finish(offset, fileIdentifier);
@@ -177,21 +183,21 @@ class Monster {
   final fb.BufferContext _bc;
   final int _bcOffset;
 
-  Vec3 get pos => Vec3.reader.vTableGet(_bc, _bcOffset, 4, null);
+  Vec3? get pos => Vec3.reader.vTableGetNullable(_bc, _bcOffset, 4);
   int get mana => const fb.Int16Reader().vTableGet(_bc, _bcOffset, 6, 150);
   int get hp => const fb.Int16Reader().vTableGet(_bc, _bcOffset, 8, 100);
-  String get name => const fb.StringReader().vTableGet(_bc, _bcOffset, 10, null);
-  List<int> get inventory => const fb.ListReader<int>(const fb.Uint8Reader()).vTableGet(_bc, _bcOffset, 14, null);
-  Color get color => new Color.fromValue(const fb.Int8Reader().vTableGet(_bc, _bcOffset, 16, 2));
-  List<Weapon> get weapons => const fb.ListReader<Weapon>(Weapon.reader).vTableGet(_bc, _bcOffset, 18, null);
-  EquipmentTypeId get equippedType => new EquipmentTypeId.fromValue(const fb.Uint8Reader().vTableGet(_bc, _bcOffset, 20, 0));
-  dynamic get equipped {
+  String? get name => const fb.StringReader().vTableGetNullable(_bc, _bcOffset, 10);
+  List<int>? get inventory => const fb.ListReader<int>(const fb.Uint8Reader()).vTableGetNullable(_bc, _bcOffset, 14);
+  Color get color => Color.fromValue(const fb.Int8Reader().vTableGet(_bc, _bcOffset, 16, 2));
+  List<Weapon>? get weapons => const fb.ListReader<Weapon>(Weapon.reader).vTableGetNullable(_bc, _bcOffset, 18);
+  EquipmentTypeId? get equippedType => EquipmentTypeId._createOrNull(const fb.Uint8Reader().vTableGetNullable(_bc, _bcOffset, 20));
+  dynamic? get equipped {
     switch (equippedType?.value) {
-      case 1: return Weapon.reader.vTableGet(_bc, _bcOffset, 22, null);
+      case 1: return Weapon.reader.vTableGetNullable(_bc, _bcOffset, 22);
       default: return null;
     }
   }
-  List<Vec3> get path => const fb.ListReader<Vec3>(Vec3.reader).vTableGet(_bc, _bcOffset, 24, null);
+  List<Vec3>? get path => const fb.ListReader<Vec3>(Vec3.reader).vTableGetNullable(_bc, _bcOffset, 24);
 
   @override
   String toString() {
@@ -208,9 +214,7 @@ class _MonsterReader extends fb.TableReader<Monster> {
 }
 
 class MonsterBuilder {
-  MonsterBuilder(this.fbBuilder) {
-    assert(fbBuilder != null);
-  }
+  MonsterBuilder(this.fbBuilder) {}
 
   final fb.Builder fbBuilder;
 
@@ -222,39 +226,39 @@ class MonsterBuilder {
     fbBuilder.addStruct(0, offset);
     return fbBuilder.offset;
   }
-  int addMana(int mana) {
+  int addMana(int? mana) {
     fbBuilder.addInt16(1, mana);
     return fbBuilder.offset;
   }
-  int addHp(int hp) {
+  int addHp(int? hp) {
     fbBuilder.addInt16(2, hp);
     return fbBuilder.offset;
   }
-  int addNameOffset(int offset) {
+  int addNameOffset(int? offset) {
     fbBuilder.addOffset(3, offset);
     return fbBuilder.offset;
   }
-  int addInventoryOffset(int offset) {
+  int addInventoryOffset(int? offset) {
     fbBuilder.addOffset(5, offset);
     return fbBuilder.offset;
   }
-  int addColor(Color color) {
+  int addColor(Color? color) {
     fbBuilder.addInt8(6, color?.value);
     return fbBuilder.offset;
   }
-  int addWeaponsOffset(int offset) {
+  int addWeaponsOffset(int? offset) {
     fbBuilder.addOffset(7, offset);
     return fbBuilder.offset;
   }
-  int addEquippedType(EquipmentTypeId equippedType) {
+  int addEquippedType(EquipmentTypeId? equippedType) {
     fbBuilder.addUint8(8, equippedType?.value);
     return fbBuilder.offset;
   }
-  int addEquippedOffset(int offset) {
+  int addEquippedOffset(int? offset) {
     fbBuilder.addOffset(9, offset);
     return fbBuilder.offset;
   }
-  int addPathOffset(int offset) {
+  int addPathOffset(int? offset) {
     fbBuilder.addOffset(10, offset);
     return fbBuilder.offset;
   }
@@ -265,28 +269,28 @@ class MonsterBuilder {
 }
 
 class MonsterObjectBuilder extends fb.ObjectBuilder {
-  final Vec3ObjectBuilder _pos;
-  final int _mana;
-  final int _hp;
-  final String _name;
-  final List<int> _inventory;
-  final Color _color;
-  final List<WeaponObjectBuilder> _weapons;
-  final EquipmentTypeId _equippedType;
-  final dynamic _equipped;
-  final List<Vec3ObjectBuilder> _path;
+  final Vec3ObjectBuilder? _pos;
+  final int? _mana;
+  final int? _hp;
+  final String? _name;
+  final List<int>? _inventory;
+  final Color? _color;
+  final List<WeaponObjectBuilder>? _weapons;
+  final EquipmentTypeId? _equippedType;
+  final dynamic? _equipped;
+  final List<Vec3ObjectBuilder>? _path;
 
   MonsterObjectBuilder({
-    Vec3ObjectBuilder pos,
-    int mana,
-    int hp,
-    String name,
-    List<int> inventory,
-    Color color,
-    List<WeaponObjectBuilder> weapons,
-    EquipmentTypeId equippedType,
-    dynamic equipped,
-    List<Vec3ObjectBuilder> path,
+    Vec3ObjectBuilder? pos,
+    int? mana,
+    int? hp,
+    String? name,
+    List<int>? inventory,
+    Color? color,
+    List<WeaponObjectBuilder>? weapons,
+    EquipmentTypeId? equippedType,
+    dynamic? equipped,
+    List<Vec3ObjectBuilder>? path,
   })
       : _pos = pos,
         _mana = mana,
@@ -301,50 +305,37 @@ class MonsterObjectBuilder extends fb.ObjectBuilder {
 
   /// Finish building, and store into the [fbBuilder].
   @override
-  int finish(
-    fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-    final int nameOffset = fbBuilder.writeString(_name);
-    final int inventoryOffset = _inventory?.isNotEmpty == true
-        ? fbBuilder.writeListUint8(_inventory)
+  int finish(fb.Builder fbBuilder) {
+    final int? nameOffset = fbBuilder.writeString(_name);
+    final int? inventoryOffset = _inventory?.isNotEmpty == true
+        ? fbBuilder.writeListUint8(_inventory!)
         : null;
-    final int weaponsOffset = _weapons?.isNotEmpty == true
-        ? fbBuilder.writeList(_weapons.map((b) => b.getOrCreateOffset(fbBuilder)).toList())
+    final int? weaponsOffset = _weapons?.isNotEmpty == true
+        ? fbBuilder.writeList(_weapons!.map((b) => b.getOrCreateOffset(fbBuilder)).toList())
         : null;
-    final int equippedOffset = _equipped?.getOrCreateOffset(fbBuilder);
-    final int pathOffset = _path?.isNotEmpty == true
-        ? fbBuilder.writeListOfStructs(_path)
+    final int? equippedOffset = _equipped?.getOrCreateOffset(fbBuilder);
+    final int? pathOffset = _path?.isNotEmpty == true
+        ? fbBuilder.writeListOfStructs(_path!)
         : null;
-
     fbBuilder.startTable();
     if (_pos != null) {
-      fbBuilder.addStruct(0, _pos.finish(fbBuilder));
+      fbBuilder.addStruct(0, _pos!.finish(fbBuilder));
     }
     fbBuilder.addInt16(1, _mana);
     fbBuilder.addInt16(2, _hp);
-    if (nameOffset != null) {
-      fbBuilder.addOffset(3, nameOffset);
-    }
-    if (inventoryOffset != null) {
-      fbBuilder.addOffset(5, inventoryOffset);
-    }
+    fbBuilder.addOffset(3, nameOffset);
+    fbBuilder.addOffset(5, inventoryOffset);
     fbBuilder.addInt8(6, _color?.value);
-    if (weaponsOffset != null) {
-      fbBuilder.addOffset(7, weaponsOffset);
-    }
+    fbBuilder.addOffset(7, weaponsOffset);
     fbBuilder.addUint8(8, _equippedType?.value);
-    if (equippedOffset != null) {
-      fbBuilder.addOffset(9, equippedOffset);
-    }
-    if (pathOffset != null) {
-      fbBuilder.addOffset(10, pathOffset);
-    }
+    fbBuilder.addOffset(9, equippedOffset);
+    fbBuilder.addOffset(10, pathOffset);
     return fbBuilder.endTable();
   }
 
   /// Convenience method to serialize to byte list.
   @override
-  Uint8List toBytes([String fileIdentifier]) {
+  Uint8List toBytes([String? fileIdentifier]) {
     fb.Builder fbBuilder = new fb.Builder();
     int offset = finish(fbBuilder);
     return fbBuilder.finish(offset, fileIdentifier);
@@ -362,7 +353,7 @@ class Weapon {
   final fb.BufferContext _bc;
   final int _bcOffset;
 
-  String get name => const fb.StringReader().vTableGet(_bc, _bcOffset, 4, null);
+  String? get name => const fb.StringReader().vTableGetNullable(_bc, _bcOffset, 4);
   int get damage => const fb.Int16Reader().vTableGet(_bc, _bcOffset, 6, 0);
 
   @override
@@ -380,9 +371,7 @@ class _WeaponReader extends fb.TableReader<Weapon> {
 }
 
 class WeaponBuilder {
-  WeaponBuilder(this.fbBuilder) {
-    assert(fbBuilder != null);
-  }
+  WeaponBuilder(this.fbBuilder) {}
 
   final fb.Builder fbBuilder;
 
@@ -390,11 +379,11 @@ class WeaponBuilder {
     fbBuilder.startTable();
   }
 
-  int addNameOffset(int offset) {
+  int addNameOffset(int? offset) {
     fbBuilder.addOffset(0, offset);
     return fbBuilder.offset;
   }
-  int addDamage(int damage) {
+  int addDamage(int? damage) {
     fbBuilder.addInt16(1, damage);
     return fbBuilder.offset;
   }
@@ -405,34 +394,29 @@ class WeaponBuilder {
 }
 
 class WeaponObjectBuilder extends fb.ObjectBuilder {
-  final String _name;
-  final int _damage;
+  final String? _name;
+  final int? _damage;
 
   WeaponObjectBuilder({
-    String name,
-    int damage,
+    String? name,
+    int? damage,
   })
       : _name = name,
         _damage = damage;
 
   /// Finish building, and store into the [fbBuilder].
   @override
-  int finish(
-    fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-    final int nameOffset = fbBuilder.writeString(_name);
-
+  int finish(fb.Builder fbBuilder) {
+    final int? nameOffset = fbBuilder.writeString(_name);
     fbBuilder.startTable();
-    if (nameOffset != null) {
-      fbBuilder.addOffset(0, nameOffset);
-    }
+    fbBuilder.addOffset(0, nameOffset);
     fbBuilder.addInt16(1, _damage);
     return fbBuilder.endTable();
   }
 
   /// Convenience method to serialize to byte list.
   @override
-  Uint8List toBytes([String fileIdentifier]) {
+  Uint8List toBytes([String? fileIdentifier]) {
     fb.Builder fbBuilder = new fb.Builder();
     int offset = finish(fbBuilder);
     return fbBuilder.finish(offset, fileIdentifier);
diff --git a/samples/dart_sample.sh b/samples/dart_sample.sh
index 561606668a2..bc4328ede27 100755
--- a/samples/dart_sample.sh
+++ b/samples/dart_sample.sh
@@ -1,4 +1,5 @@
 #!/bin/bash
+set -euo
 #
 # Copyright 2018 Dan Field. All rights reserved.
 #
diff --git a/tests/monster_extra_my_game_generated.dart b/tests/monster_extra_my_game_generated.dart
index 11bf3af8a73..7afa43299b0 100644
--- a/tests/monster_extra_my_game_generated.dart
+++ b/tests/monster_extra_my_game_generated.dart
@@ -1,5 +1,5 @@
 // automatically generated by the FlatBuffers compiler, do not modify
-// ignore_for_file: unused_import, unused_field, unused_local_variable
+// ignore_for_file: unused_import, unused_field, unused_element, unused_local_variable
 
 library my_game;
 
@@ -27,8 +27,8 @@ class MonsterExtra {
   double get f1 => const fb.Float32Reader().vTableGet(_bc, _bcOffset, 14, double.nan);
   double get f2 => const fb.Float32Reader().vTableGet(_bc, _bcOffset, 16, double.infinity);
   double get f3 => const fb.Float32Reader().vTableGet(_bc, _bcOffset, 18, double.negativeInfinity);
-  List<double> get dvec => const fb.ListReader<double>(const fb.Float64Reader()).vTableGet(_bc, _bcOffset, 20, null);
-  List<double> get fvec => const fb.ListReader<double>(const fb.Float32Reader()).vTableGet(_bc, _bcOffset, 22, null);
+  List<double>? get dvec => const fb.ListReader<double>(const fb.Float64Reader()).vTableGetNullable(_bc, _bcOffset, 20);
+  List<double>? get fvec => const fb.ListReader<double>(const fb.Float32Reader()).vTableGetNullable(_bc, _bcOffset, 22);
 
   @override
   String toString() {
@@ -47,7 +47,7 @@ class MonsterExtra {
       dvec: dvec,
       fvec: fvec);
 
-  static int pack(fb.Builder fbBuilder, MonsterExtraT object) {
+  static int pack(fb.Builder fbBuilder, MonsterExtraT? object) {
     if (object == null) return 0;
     return object.pack(fbBuilder);
   }
@@ -62,30 +62,28 @@ class MonsterExtraT {
   double f1;
   double f2;
   double f3;
-  List<double> dvec;
-  List<double> fvec;
+  List<double>? dvec;
+  List<double>? fvec;
 
   MonsterExtraT({
-      this.d0,
-      this.d1,
-      this.d2,
-      this.d3,
-      this.f0,
-      this.f1,
-      this.f2,
-      this.f3,
+      this.d0 = double.nan,
+      this.d1 = double.nan,
+      this.d2 = double.infinity,
+      this.d3 = double.negativeInfinity,
+      this.f0 = double.nan,
+      this.f1 = double.nan,
+      this.f2 = double.infinity,
+      this.f3 = double.negativeInfinity,
       this.dvec,
       this.fvec});
 
   int pack(fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-    final int dvecOffset = dvec?.isNotEmpty == true
-        ? fbBuilder.writeListFloat64(dvec)
+    final int? dvecOffset = dvec?.isNotEmpty == true
+        ? fbBuilder.writeListFloat64(dvec!)
         : null;
-    final int fvecOffset = fvec?.isNotEmpty == true
-        ? fbBuilder.writeListFloat32(fvec)
+    final int? fvecOffset = fvec?.isNotEmpty == true
+        ? fbBuilder.writeListFloat32(fvec!)
         : null;
-
     fbBuilder.startTable();
     fbBuilder.addFloat64(0, d0);
     fbBuilder.addFloat64(1, d1);
@@ -95,12 +93,8 @@ class MonsterExtraT {
     fbBuilder.addFloat32(5, f1);
     fbBuilder.addFloat32(6, f2);
     fbBuilder.addFloat32(7, f3);
-    if (dvecOffset != null) {
-      fbBuilder.addOffset(8, dvecOffset);
-    }
-    if (fvecOffset != null) {
-      fbBuilder.addOffset(9, fvecOffset);
-    }
+    fbBuilder.addOffset(8, dvecOffset);
+    fbBuilder.addOffset(9, fvecOffset);
     return fbBuilder.endTable();
   }
 
@@ -119,9 +113,7 @@ class _MonsterExtraReader extends fb.TableReader<MonsterExtra> {
 }
 
 class MonsterExtraBuilder {
-  MonsterExtraBuilder(this.fbBuilder) {
-    assert(fbBuilder != null);
-  }
+  MonsterExtraBuilder(this.fbBuilder) {}
 
   final fb.Builder fbBuilder;
 
@@ -129,43 +121,43 @@ class MonsterExtraBuilder {
     fbBuilder.startTable();
   }
 
-  int addD0(double d0) {
+  int addD0(double? d0) {
     fbBuilder.addFloat64(0, d0);
     return fbBuilder.offset;
   }
-  int addD1(double d1) {
+  int addD1(double? d1) {
     fbBuilder.addFloat64(1, d1);
     return fbBuilder.offset;
   }
-  int addD2(double d2) {
+  int addD2(double? d2) {
     fbBuilder.addFloat64(2, d2);
     return fbBuilder.offset;
   }
-  int addD3(double d3) {
+  int addD3(double? d3) {
     fbBuilder.addFloat64(3, d3);
     return fbBuilder.offset;
   }
-  int addF0(double f0) {
+  int addF0(double? f0) {
     fbBuilder.addFloat32(4, f0);
     return fbBuilder.offset;
   }
-  int addF1(double f1) {
+  int addF1(double? f1) {
     fbBuilder.addFloat32(5, f1);
     return fbBuilder.offset;
   }
-  int addF2(double f2) {
+  int addF2(double? f2) {
     fbBuilder.addFloat32(6, f2);
     return fbBuilder.offset;
   }
-  int addF3(double f3) {
+  int addF3(double? f3) {
     fbBuilder.addFloat32(7, f3);
     return fbBuilder.offset;
   }
-  int addDvecOffset(int offset) {
+  int addDvecOffset(int? offset) {
     fbBuilder.addOffset(8, offset);
     return fbBuilder.offset;
   }
-  int addFvecOffset(int offset) {
+  int addFvecOffset(int? offset) {
     fbBuilder.addOffset(9, offset);
     return fbBuilder.offset;
   }
@@ -176,28 +168,28 @@ class MonsterExtraBuilder {
 }
 
 class MonsterExtraObjectBuilder extends fb.ObjectBuilder {
-  final double _d0;
-  final double _d1;
-  final double _d2;
-  final double _d3;
-  final double _f0;
-  final double _f1;
-  final double _f2;
-  final double _f3;
-  final List<double> _dvec;
-  final List<double> _fvec;
+  final double? _d0;
+  final double? _d1;
+  final double? _d2;
+  final double? _d3;
+  final double? _f0;
+  final double? _f1;
+  final double? _f2;
+  final double? _f3;
+  final List<double>? _dvec;
+  final List<double>? _fvec;
 
   MonsterExtraObjectBuilder({
-    double d0,
-    double d1,
-    double d2,
-    double d3,
-    double f0,
-    double f1,
-    double f2,
-    double f3,
-    List<double> dvec,
-    List<double> fvec,
+    double? d0,
+    double? d1,
+    double? d2,
+    double? d3,
+    double? f0,
+    double? f1,
+    double? f2,
+    double? f3,
+    List<double>? dvec,
+    List<double>? fvec,
   })
       : _d0 = d0,
         _d1 = d1,
@@ -212,16 +204,13 @@ class MonsterExtraObjectBuilder extends fb.ObjectBuilder {
 
   /// Finish building, and store into the [fbBuilder].
   @override
-  int finish(
-    fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-    final int dvecOffset = _dvec?.isNotEmpty == true
-        ? fbBuilder.writeListFloat64(_dvec)
+  int finish(fb.Builder fbBuilder) {
+    final int? dvecOffset = _dvec?.isNotEmpty == true
+        ? fbBuilder.writeListFloat64(_dvec!)
         : null;
-    final int fvecOffset = _fvec?.isNotEmpty == true
-        ? fbBuilder.writeListFloat32(_fvec)
+    final int? fvecOffset = _fvec?.isNotEmpty == true
+        ? fbBuilder.writeListFloat32(_fvec!)
         : null;
-
     fbBuilder.startTable();
     fbBuilder.addFloat64(0, _d0);
     fbBuilder.addFloat64(1, _d1);
@@ -231,18 +220,14 @@ class MonsterExtraObjectBuilder extends fb.ObjectBuilder {
     fbBuilder.addFloat32(5, _f1);
     fbBuilder.addFloat32(6, _f2);
     fbBuilder.addFloat32(7, _f3);
-    if (dvecOffset != null) {
-      fbBuilder.addOffset(8, dvecOffset);
-    }
-    if (fvecOffset != null) {
-      fbBuilder.addOffset(9, fvecOffset);
-    }
+    fbBuilder.addOffset(8, dvecOffset);
+    fbBuilder.addOffset(9, fvecOffset);
     return fbBuilder.endTable();
   }
 
   /// Convenience method to serialize to byte list.
   @override
-  Uint8List toBytes([String fileIdentifier]) {
+  Uint8List toBytes([String? fileIdentifier]) {
     fb.Builder fbBuilder = new fb.Builder();
     int offset = finish(fbBuilder);
     return fbBuilder.finish(offset, fileIdentifier);
diff --git a/tests/monster_test_my_game.example2_generated.dart b/tests/monster_test_my_game.example2_generated.dart
index d1c6a03abf1..92d7c911bea 100644
--- a/tests/monster_test_my_game.example2_generated.dart
+++ b/tests/monster_test_my_game.example2_generated.dart
@@ -1,5 +1,5 @@
 // automatically generated by the FlatBuffers compiler, do not modify
-// ignore_for_file: unused_import, unused_field, unused_local_variable
+// ignore_for_file: unused_import, unused_field, unused_element, unused_local_variable
 
 library my_game.example2;
 
@@ -29,7 +29,7 @@ class Monster {
 
   MonsterT unpack() => MonsterT();
 
-  static int pack(fb.Builder fbBuilder, MonsterT object) {
+  static int pack(fb.Builder fbBuilder, MonsterT? object) {
     if (object == null) return 0;
     return object.pack(fbBuilder);
   }
@@ -37,8 +37,6 @@ class Monster {
 
 class MonsterT {
   int pack(fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-
     fbBuilder.startTable();
     return fbBuilder.endTable();
   }
@@ -63,17 +61,14 @@ class MonsterObjectBuilder extends fb.ObjectBuilder {
 
   /// Finish building, and store into the [fbBuilder].
   @override
-  int finish(
-    fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-
+  int finish(fb.Builder fbBuilder) {
     fbBuilder.startTable();
     return fbBuilder.endTable();
   }
 
   /// Convenience method to serialize to byte list.
   @override
-  Uint8List toBytes([String fileIdentifier]) {
+  Uint8List toBytes([String? fileIdentifier]) {
     fb.Builder fbBuilder = new fb.Builder();
     int offset = finish(fbBuilder);
     return fbBuilder.finish(offset, fileIdentifier);
diff --git a/tests/monster_test_my_game.example_generated.dart b/tests/monster_test_my_game.example_generated.dart
index 75302f9fe47..36ada7d5f19 100644
--- a/tests/monster_test_my_game.example_generated.dart
+++ b/tests/monster_test_my_game.example_generated.dart
@@ -1,5 +1,5 @@
 // automatically generated by the FlatBuffers compiler, do not modify
-// ignore_for_file: unused_import, unused_field, unused_local_variable
+// ignore_for_file: unused_import, unused_field, unused_element, unused_local_variable
 
 library my_game.example;
 
@@ -15,13 +15,16 @@ class Color {
   const Color._(this.value);
 
   factory Color.fromValue(int value) {
-    if (value == null) value = 0;
-    if (!values.containsKey(value)) {
+    final result = values[value];
+    if (result == null) {
       throw new StateError('Invalid value $value for bit flag enum Color');
     }
-    return values[value];
+    return result;
   }
 
+  static Color? _createOrNull(int? value) => 
+      value == null ? null : Color.fromValue(value);
+
   static bool containsValue(int value) => values.containsKey(value);
 
   static const Color Red = const Color._(1);
@@ -32,7 +35,10 @@ class Color {
 
   ///  \brief color Blue (1u << 3)
   static const Color Blue = const Color._(8);
-  static const Map<int,Color> values = {1: Red,2: Green,8: Blue,};
+  static const Map<int, Color> values = {
+    1: Red,
+    2: Green,
+    8: Blue};
 
   static const fb.Reader<Color> reader = const _ColorReader();
 
@@ -58,13 +64,16 @@ class Race {
   const Race._(this.value);
 
   factory Race.fromValue(int value) {
-    if (value == null) value = 0;
-    if (!values.containsKey(value)) {
+    final result = values[value];
+    if (result == null) {
       throw new StateError('Invalid value $value for bit flag enum Race');
     }
-    return values[value];
+    return result;
   }
 
+  static Race? _createOrNull(int? value) => 
+      value == null ? null : Race.fromValue(value);
+
   static const int minValue = -1;
   static const int maxValue = 2;
   static bool containsValue(int value) => values.containsKey(value);
@@ -73,7 +82,11 @@ class Race {
   static const Race Human = const Race._(0);
   static const Race Dwarf = const Race._(1);
   static const Race Elf = const Race._(2);
-  static const Map<int,Race> values = {-1: None,0: Human,1: Dwarf,2: Elf,};
+  static const Map<int, Race> values = {
+    -1: None,
+    0: Human,
+    1: Dwarf,
+    2: Elf};
 
   static const fb.Reader<Race> reader = const _RaceReader();
 
@@ -99,13 +112,16 @@ class AnyTypeId {
   const AnyTypeId._(this.value);
 
   factory AnyTypeId.fromValue(int value) {
-    if (value == null) value = 0;
-    if (!values.containsKey(value)) {
+    final result = values[value];
+    if (result == null) {
       throw new StateError('Invalid value $value for bit flag enum AnyTypeId');
     }
-    return values[value];
+    return result;
   }
 
+  static AnyTypeId? _createOrNull(int? value) => 
+      value == null ? null : AnyTypeId.fromValue(value);
+
   static const int minValue = 0;
   static const int maxValue = 3;
   static bool containsValue(int value) => values.containsKey(value);
@@ -114,7 +130,11 @@ class AnyTypeId {
   static const AnyTypeId Monster = const AnyTypeId._(1);
   static const AnyTypeId TestSimpleTableWithEnum = const AnyTypeId._(2);
   static const AnyTypeId MyGame_Example2_Monster = const AnyTypeId._(3);
-  static const Map<int,AnyTypeId> values = {0: NONE,1: Monster,2: TestSimpleTableWithEnum,3: MyGame_Example2_Monster,};
+  static const Map<int, AnyTypeId> values = {
+    0: NONE,
+    1: Monster,
+    2: TestSimpleTableWithEnum,
+    3: MyGame_Example2_Monster};
 
   static const fb.Reader<AnyTypeId> reader = const _AnyTypeIdReader();
 
@@ -140,13 +160,16 @@ class AnyUniqueAliasesTypeId {
   const AnyUniqueAliasesTypeId._(this.value);
 
   factory AnyUniqueAliasesTypeId.fromValue(int value) {
-    if (value == null) value = 0;
-    if (!values.containsKey(value)) {
+    final result = values[value];
+    if (result == null) {
       throw new StateError('Invalid value $value for bit flag enum AnyUniqueAliasesTypeId');
     }
-    return values[value];
+    return result;
   }
 
+  static AnyUniqueAliasesTypeId? _createOrNull(int? value) => 
+      value == null ? null : AnyUniqueAliasesTypeId.fromValue(value);
+
   static const int minValue = 0;
   static const int maxValue = 3;
   static bool containsValue(int value) => values.containsKey(value);
@@ -155,7 +178,11 @@ class AnyUniqueAliasesTypeId {
   static const AnyUniqueAliasesTypeId M = const AnyUniqueAliasesTypeId._(1);
   static const AnyUniqueAliasesTypeId TS = const AnyUniqueAliasesTypeId._(2);
   static const AnyUniqueAliasesTypeId M2 = const AnyUniqueAliasesTypeId._(3);
-  static const Map<int,AnyUniqueAliasesTypeId> values = {0: NONE,1: M,2: TS,3: M2,};
+  static const Map<int, AnyUniqueAliasesTypeId> values = {
+    0: NONE,
+    1: M,
+    2: TS,
+    3: M2};
 
   static const fb.Reader<AnyUniqueAliasesTypeId> reader = const _AnyUniqueAliasesTypeIdReader();
 
@@ -181,13 +208,16 @@ class AnyAmbiguousAliasesTypeId {
   const AnyAmbiguousAliasesTypeId._(this.value);
 
   factory AnyAmbiguousAliasesTypeId.fromValue(int value) {
-    if (value == null) value = 0;
-    if (!values.containsKey(value)) {
+    final result = values[value];
+    if (result == null) {
       throw new StateError('Invalid value $value for bit flag enum AnyAmbiguousAliasesTypeId');
     }
-    return values[value];
+    return result;
   }
 
+  static AnyAmbiguousAliasesTypeId? _createOrNull(int? value) => 
+      value == null ? null : AnyAmbiguousAliasesTypeId.fromValue(value);
+
   static const int minValue = 0;
   static const int maxValue = 3;
   static bool containsValue(int value) => values.containsKey(value);
@@ -196,7 +226,11 @@ class AnyAmbiguousAliasesTypeId {
   static const AnyAmbiguousAliasesTypeId M1 = const AnyAmbiguousAliasesTypeId._(1);
   static const AnyAmbiguousAliasesTypeId M2 = const AnyAmbiguousAliasesTypeId._(2);
   static const AnyAmbiguousAliasesTypeId M3 = const AnyAmbiguousAliasesTypeId._(3);
-  static const Map<int,AnyAmbiguousAliasesTypeId> values = {0: NONE,1: M1,2: M2,3: M3,};
+  static const Map<int, AnyAmbiguousAliasesTypeId> values = {
+    0: NONE,
+    1: M1,
+    2: M2,
+    3: M3};
 
   static const fb.Reader<AnyAmbiguousAliasesTypeId> reader = const _AnyAmbiguousAliasesTypeIdReader();
 
@@ -237,7 +271,7 @@ class Test {
       a: a,
       b: b);
 
-  static int pack(fb.Builder fbBuilder, TestT object) {
+  static int pack(fb.Builder fbBuilder, TestT? object) {
     if (object == null) return 0;
     return object.pack(fbBuilder);
   }
@@ -248,12 +282,10 @@ class TestT {
   int b;
 
   TestT({
-      this.a,
-      this.b});
+      required this.a,
+      required this.b});
 
   int pack(fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-
     fbBuilder.pad(1);
     fbBuilder.putInt8(b);
     fbBuilder.putInt16(a);
@@ -278,9 +310,7 @@ class _TestReader extends fb.StructReader<Test> {
 }
 
 class TestBuilder {
-  TestBuilder(this.fbBuilder) {
-    assert(fbBuilder != null);
-  }
+  TestBuilder(this.fbBuilder) {}
 
   final fb.Builder fbBuilder;
 
@@ -298,18 +328,15 @@ class TestObjectBuilder extends fb.ObjectBuilder {
   final int _b;
 
   TestObjectBuilder({
-    int a,
-    int b,
+    required int a,
+    required int b,
   })
       : _a = a,
         _b = b;
 
   /// Finish building, and store into the [fbBuilder].
   @override
-  int finish(
-    fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-
+  int finish(fb.Builder fbBuilder) {
     fbBuilder.pad(1);
     fbBuilder.putInt8(_b);
     fbBuilder.putInt16(_a);
@@ -318,7 +345,7 @@ class TestObjectBuilder extends fb.ObjectBuilder {
 
   /// Convenience method to serialize to byte list.
   @override
-  Uint8List toBytes([String fileIdentifier]) {
+  Uint8List toBytes([String? fileIdentifier]) {
     fb.Builder fbBuilder = new fb.Builder();
     int offset = finish(fbBuilder);
     return fbBuilder.finish(offset, fileIdentifier);
@@ -336,7 +363,7 @@ class TestSimpleTableWithEnum {
   final fb.BufferContext _bc;
   final int _bcOffset;
 
-  Color get color => new Color.fromValue(const fb.Uint8Reader().vTableGet(_bc, _bcOffset, 4, 2));
+  Color get color => Color.fromValue(const fb.Uint8Reader().vTableGet(_bc, _bcOffset, 4, 2));
 
   @override
   String toString() {
@@ -346,7 +373,7 @@ class TestSimpleTableWithEnum {
   TestSimpleTableWithEnumT unpack() => TestSimpleTableWithEnumT(
       color: color);
 
-  static int pack(fb.Builder fbBuilder, TestSimpleTableWithEnumT object) {
+  static int pack(fb.Builder fbBuilder, TestSimpleTableWithEnumT? object) {
     if (object == null) return 0;
     return object.pack(fbBuilder);
   }
@@ -356,13 +383,11 @@ class TestSimpleTableWithEnumT {
   Color color;
 
   TestSimpleTableWithEnumT({
-      this.color});
+      this.color = Color.Green});
 
   int pack(fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-
     fbBuilder.startTable();
-    fbBuilder.addUint8(0, color?.value);
+    fbBuilder.addUint8(0, color.value);
     return fbBuilder.endTable();
   }
 
@@ -381,9 +406,7 @@ class _TestSimpleTableWithEnumReader extends fb.TableReader<TestSimpleTableWithE
 }
 
 class TestSimpleTableWithEnumBuilder {
-  TestSimpleTableWithEnumBuilder(this.fbBuilder) {
-    assert(fbBuilder != null);
-  }
+  TestSimpleTableWithEnumBuilder(this.fbBuilder) {}
 
   final fb.Builder fbBuilder;
 
@@ -391,7 +414,7 @@ class TestSimpleTableWithEnumBuilder {
     fbBuilder.startTable();
   }
 
-  int addColor(Color color) {
+  int addColor(Color? color) {
     fbBuilder.addUint8(0, color?.value);
     return fbBuilder.offset;
   }
@@ -402,19 +425,16 @@ class TestSimpleTableWithEnumBuilder {
 }
 
 class TestSimpleTableWithEnumObjectBuilder extends fb.ObjectBuilder {
-  final Color _color;
+  final Color? _color;
 
   TestSimpleTableWithEnumObjectBuilder({
-    Color color,
+    Color? color,
   })
       : _color = color;
 
   /// Finish building, and store into the [fbBuilder].
   @override
-  int finish(
-    fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-
+  int finish(fb.Builder fbBuilder) {
     fbBuilder.startTable();
     fbBuilder.addUint8(0, _color?.value);
     return fbBuilder.endTable();
@@ -422,7 +442,7 @@ class TestSimpleTableWithEnumObjectBuilder extends fb.ObjectBuilder {
 
   /// Convenience method to serialize to byte list.
   @override
-  Uint8List toBytes([String fileIdentifier]) {
+  Uint8List toBytes([String? fileIdentifier]) {
     fb.Builder fbBuilder = new fb.Builder();
     int offset = finish(fbBuilder);
     return fbBuilder.finish(offset, fileIdentifier);
@@ -440,7 +460,7 @@ class Vec3 {
   double get y => const fb.Float32Reader().read(_bc, _bcOffset + 4);
   double get z => const fb.Float32Reader().read(_bc, _bcOffset + 8);
   double get test1 => const fb.Float64Reader().read(_bc, _bcOffset + 16);
-  Color get test2 => new Color.fromValue(const fb.Uint8Reader().read(_bc, _bcOffset + 24));
+  Color get test2 => Color.fromValue(const fb.Uint8Reader().read(_bc, _bcOffset + 24));
   Test get test3 => Test.reader.read(_bc, _bcOffset + 26);
 
   @override
@@ -454,9 +474,9 @@ class Vec3 {
       z: z,
       test1: test1,
       test2: test2,
-      test3: test3?.unpack());
+      test3: test3.unpack());
 
-  static int pack(fb.Builder fbBuilder, Vec3T object) {
+  static int pack(fb.Builder fbBuilder, Vec3T? object) {
     if (object == null) return 0;
     return object.pack(fbBuilder);
   }
@@ -471,20 +491,18 @@ class Vec3T {
   TestT test3;
 
   Vec3T({
-      this.x,
-      this.y,
-      this.z,
-      this.test1,
-      this.test2,
-      this.test3});
+      required this.x,
+      required this.y,
+      required this.z,
+      required this.test1,
+      required this.test2,
+      required this.test3});
 
   int pack(fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-
     fbBuilder.pad(2);
     test3.pack(fbBuilder);
     fbBuilder.pad(1);
-    fbBuilder.putUint8(test2?.value);
+    fbBuilder.putUint8(test2.value);
     fbBuilder.putFloat64(test1);
     fbBuilder.pad(4);
     fbBuilder.putFloat32(z);
@@ -511,9 +529,7 @@ class _Vec3Reader extends fb.StructReader<Vec3> {
 }
 
 class Vec3Builder {
-  Vec3Builder(this.fbBuilder) {
-    assert(fbBuilder != null);
-  }
+  Vec3Builder(this.fbBuilder) {}
 
   final fb.Builder fbBuilder;
 
@@ -521,7 +537,7 @@ class Vec3Builder {
     fbBuilder.pad(2);
     test3();
     fbBuilder.pad(1);
-    fbBuilder.putUint8(test2?.value);
+    fbBuilder.putUint8(test2.value);
     fbBuilder.putFloat64(test1);
     fbBuilder.pad(4);
     fbBuilder.putFloat32(z);
@@ -541,12 +557,12 @@ class Vec3ObjectBuilder extends fb.ObjectBuilder {
   final TestObjectBuilder _test3;
 
   Vec3ObjectBuilder({
-    double x,
-    double y,
-    double z,
-    double test1,
-    Color test2,
-    TestObjectBuilder test3,
+    required double x,
+    required double y,
+    required double z,
+    required double test1,
+    required Color test2,
+    required TestObjectBuilder test3,
   })
       : _x = x,
         _y = y,
@@ -557,14 +573,11 @@ class Vec3ObjectBuilder extends fb.ObjectBuilder {
 
   /// Finish building, and store into the [fbBuilder].
   @override
-  int finish(
-    fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-
+  int finish(fb.Builder fbBuilder) {
     fbBuilder.pad(2);
     _test3.finish(fbBuilder);
     fbBuilder.pad(1);
-    fbBuilder.putUint8(_test2?.value);
+    fbBuilder.putUint8(_test2.value);
     fbBuilder.putFloat64(_test1);
     fbBuilder.pad(4);
     fbBuilder.putFloat32(_z);
@@ -575,7 +588,7 @@ class Vec3ObjectBuilder extends fb.ObjectBuilder {
 
   /// Convenience method to serialize to byte list.
   @override
-  Uint8List toBytes([String fileIdentifier]) {
+  Uint8List toBytes([String? fileIdentifier]) {
     fb.Builder fbBuilder = new fb.Builder();
     int offset = finish(fbBuilder);
     return fbBuilder.finish(offset, fileIdentifier);
@@ -601,7 +614,7 @@ class Ability {
       id: id,
       distance: distance);
 
-  static int pack(fb.Builder fbBuilder, AbilityT object) {
+  static int pack(fb.Builder fbBuilder, AbilityT? object) {
     if (object == null) return 0;
     return object.pack(fbBuilder);
   }
@@ -612,12 +625,10 @@ class AbilityT {
   int distance;
 
   AbilityT({
-      this.id,
-      this.distance});
+      required this.id,
+      required this.distance});
 
   int pack(fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-
     fbBuilder.putUint32(distance);
     fbBuilder.putUint32(id);
     return fbBuilder.offset;
@@ -641,9 +652,7 @@ class _AbilityReader extends fb.StructReader<Ability> {
 }
 
 class AbilityBuilder {
-  AbilityBuilder(this.fbBuilder) {
-    assert(fbBuilder != null);
-  }
+  AbilityBuilder(this.fbBuilder) {}
 
   final fb.Builder fbBuilder;
 
@@ -660,18 +669,15 @@ class AbilityObjectBuilder extends fb.ObjectBuilder {
   final int _distance;
 
   AbilityObjectBuilder({
-    int id,
-    int distance,
+    required int id,
+    required int distance,
   })
       : _id = id,
         _distance = distance;
 
   /// Finish building, and store into the [fbBuilder].
   @override
-  int finish(
-    fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-
+  int finish(fb.Builder fbBuilder) {
     fbBuilder.putUint32(_distance);
     fbBuilder.putUint32(_id);
     return fbBuilder.offset;
@@ -679,7 +685,7 @@ class AbilityObjectBuilder extends fb.ObjectBuilder {
 
   /// Convenience method to serialize to byte list.
   @override
-  Uint8List toBytes([String fileIdentifier]) {
+  Uint8List toBytes([String? fileIdentifier]) {
     fb.Builder fbBuilder = new fb.Builder();
     int offset = finish(fbBuilder);
     return fbBuilder.finish(offset, fileIdentifier);
@@ -703,11 +709,11 @@ class StructOfStructs {
   }
 
   StructOfStructsT unpack() => StructOfStructsT(
-      a: a?.unpack(),
-      b: b?.unpack(),
-      c: c?.unpack());
+      a: a.unpack(),
+      b: b.unpack(),
+      c: c.unpack());
 
-  static int pack(fb.Builder fbBuilder, StructOfStructsT object) {
+  static int pack(fb.Builder fbBuilder, StructOfStructsT? object) {
     if (object == null) return 0;
     return object.pack(fbBuilder);
   }
@@ -719,13 +725,11 @@ class StructOfStructsT {
   AbilityT c;
 
   StructOfStructsT({
-      this.a,
-      this.b,
-      this.c});
+      required this.a,
+      required this.b,
+      required this.c});
 
   int pack(fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-
     c.pack(fbBuilder);
     b.pack(fbBuilder);
     a.pack(fbBuilder);
@@ -750,9 +754,7 @@ class _StructOfStructsReader extends fb.StructReader<StructOfStructs> {
 }
 
 class StructOfStructsBuilder {
-  StructOfStructsBuilder(this.fbBuilder) {
-    assert(fbBuilder != null);
-  }
+  StructOfStructsBuilder(this.fbBuilder) {}
 
   final fb.Builder fbBuilder;
 
@@ -771,9 +773,9 @@ class StructOfStructsObjectBuilder extends fb.ObjectBuilder {
   final AbilityObjectBuilder _c;
 
   StructOfStructsObjectBuilder({
-    AbilityObjectBuilder a,
-    TestObjectBuilder b,
-    AbilityObjectBuilder c,
+    required AbilityObjectBuilder a,
+    required TestObjectBuilder b,
+    required AbilityObjectBuilder c,
   })
       : _a = a,
         _b = b,
@@ -781,10 +783,7 @@ class StructOfStructsObjectBuilder extends fb.ObjectBuilder {
 
   /// Finish building, and store into the [fbBuilder].
   @override
-  int finish(
-    fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-
+  int finish(fb.Builder fbBuilder) {
     _c.finish(fbBuilder);
     _b.finish(fbBuilder);
     _a.finish(fbBuilder);
@@ -793,7 +792,7 @@ class StructOfStructsObjectBuilder extends fb.ObjectBuilder {
 
   /// Convenience method to serialize to byte list.
   @override
-  Uint8List toBytes([String fileIdentifier]) {
+  Uint8List toBytes([String? fileIdentifier]) {
     fb.Builder fbBuilder = new fb.Builder();
     int offset = finish(fbBuilder);
     return fbBuilder.finish(offset, fileIdentifier);
@@ -811,7 +810,7 @@ class Stat {
   final fb.BufferContext _bc;
   final int _bcOffset;
 
-  String get id => const fb.StringReader().vTableGet(_bc, _bcOffset, 4, null);
+  String? get id => const fb.StringReader().vTableGetNullable(_bc, _bcOffset, 4);
   int get val => const fb.Int64Reader().vTableGet(_bc, _bcOffset, 6, 0);
   int get count => const fb.Uint16Reader().vTableGet(_bc, _bcOffset, 8, 0);
 
@@ -825,30 +824,26 @@ class Stat {
       val: val,
       count: count);
 
-  static int pack(fb.Builder fbBuilder, StatT object) {
+  static int pack(fb.Builder fbBuilder, StatT? object) {
     if (object == null) return 0;
     return object.pack(fbBuilder);
   }
 }
 
 class StatT {
-  String id;
+  String? id;
   int val;
   int count;
 
   StatT({
       this.id,
-      this.val,
-      this.count});
+      this.val = 0,
+      this.count = 0});
 
   int pack(fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-    final int idOffset = fbBuilder.writeString(id);
-
+    final int? idOffset = fbBuilder.writeString(id);
     fbBuilder.startTable();
-    if (idOffset != null) {
-      fbBuilder.addOffset(0, idOffset);
-    }
+    fbBuilder.addOffset(0, idOffset);
     fbBuilder.addInt64(1, val);
     fbBuilder.addUint16(2, count);
     return fbBuilder.endTable();
@@ -869,9 +864,7 @@ class _StatReader extends fb.TableReader<Stat> {
 }
 
 class StatBuilder {
-  StatBuilder(this.fbBuilder) {
-    assert(fbBuilder != null);
-  }
+  StatBuilder(this.fbBuilder) {}
 
   final fb.Builder fbBuilder;
 
@@ -879,15 +872,15 @@ class StatBuilder {
     fbBuilder.startTable();
   }
 
-  int addIdOffset(int offset) {
+  int addIdOffset(int? offset) {
     fbBuilder.addOffset(0, offset);
     return fbBuilder.offset;
   }
-  int addVal(int val) {
+  int addVal(int? val) {
     fbBuilder.addInt64(1, val);
     return fbBuilder.offset;
   }
-  int addCount(int count) {
+  int addCount(int? count) {
     fbBuilder.addUint16(2, count);
     return fbBuilder.offset;
   }
@@ -898,14 +891,14 @@ class StatBuilder {
 }
 
 class StatObjectBuilder extends fb.ObjectBuilder {
-  final String _id;
-  final int _val;
-  final int _count;
+  final String? _id;
+  final int? _val;
+  final int? _count;
 
   StatObjectBuilder({
-    String id,
-    int val,
-    int count,
+    String? id,
+    int? val,
+    int? count,
   })
       : _id = id,
         _val = val,
@@ -913,15 +906,10 @@ class StatObjectBuilder extends fb.ObjectBuilder {
 
   /// Finish building, and store into the [fbBuilder].
   @override
-  int finish(
-    fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-    final int idOffset = fbBuilder.writeString(_id);
-
+  int finish(fb.Builder fbBuilder) {
+    final int? idOffset = fbBuilder.writeString(_id);
     fbBuilder.startTable();
-    if (idOffset != null) {
-      fbBuilder.addOffset(0, idOffset);
-    }
+    fbBuilder.addOffset(0, idOffset);
     fbBuilder.addInt64(1, _val);
     fbBuilder.addUint16(2, _count);
     return fbBuilder.endTable();
@@ -929,7 +917,7 @@ class StatObjectBuilder extends fb.ObjectBuilder {
 
   /// Convenience method to serialize to byte list.
   @override
-  Uint8List toBytes([String fileIdentifier]) {
+  Uint8List toBytes([String? fileIdentifier]) {
     fb.Builder fbBuilder = new fb.Builder();
     int offset = finish(fbBuilder);
     return fbBuilder.finish(offset, fileIdentifier);
@@ -957,7 +945,7 @@ class Referrable {
   ReferrableT unpack() => ReferrableT(
       id: id);
 
-  static int pack(fb.Builder fbBuilder, ReferrableT object) {
+  static int pack(fb.Builder fbBuilder, ReferrableT? object) {
     if (object == null) return 0;
     return object.pack(fbBuilder);
   }
@@ -967,11 +955,9 @@ class ReferrableT {
   int id;
 
   ReferrableT({
-      this.id});
+      this.id = 0});
 
   int pack(fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-
     fbBuilder.startTable();
     fbBuilder.addUint64(0, id);
     return fbBuilder.endTable();
@@ -992,9 +978,7 @@ class _ReferrableReader extends fb.TableReader<Referrable> {
 }
 
 class ReferrableBuilder {
-  ReferrableBuilder(this.fbBuilder) {
-    assert(fbBuilder != null);
-  }
+  ReferrableBuilder(this.fbBuilder) {}
 
   final fb.Builder fbBuilder;
 
@@ -1002,7 +986,7 @@ class ReferrableBuilder {
     fbBuilder.startTable();
   }
 
-  int addId(int id) {
+  int addId(int? id) {
     fbBuilder.addUint64(0, id);
     return fbBuilder.offset;
   }
@@ -1013,19 +997,16 @@ class ReferrableBuilder {
 }
 
 class ReferrableObjectBuilder extends fb.ObjectBuilder {
-  final int _id;
+  final int? _id;
 
   ReferrableObjectBuilder({
-    int id,
+    int? id,
   })
       : _id = id;
 
   /// Finish building, and store into the [fbBuilder].
   @override
-  int finish(
-    fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-
+  int finish(fb.Builder fbBuilder) {
     fbBuilder.startTable();
     fbBuilder.addUint64(0, _id);
     return fbBuilder.endTable();
@@ -1033,7 +1014,7 @@ class ReferrableObjectBuilder extends fb.ObjectBuilder {
 
   /// Convenience method to serialize to byte list.
   @override
-  Uint8List toBytes([String fileIdentifier]) {
+  Uint8List toBytes([String? fileIdentifier]) {
     fb.Builder fbBuilder = new fb.Builder();
     int offset = finish(fbBuilder);
     return fbBuilder.finish(offset, fileIdentifier);
@@ -1052,29 +1033,29 @@ class Monster {
   final fb.BufferContext _bc;
   final int _bcOffset;
 
-  Vec3 get pos => Vec3.reader.vTableGet(_bc, _bcOffset, 4, null);
+  Vec3? get pos => Vec3.reader.vTableGetNullable(_bc, _bcOffset, 4);
   int get mana => const fb.Int16Reader().vTableGet(_bc, _bcOffset, 6, 150);
   int get hp => const fb.Int16Reader().vTableGet(_bc, _bcOffset, 8, 100);
-  String get name => const fb.StringReader().vTableGet(_bc, _bcOffset, 10, null);
-  List<int> get inventory => const fb.ListReader<int>(const fb.Uint8Reader()).vTableGet(_bc, _bcOffset, 14, null);
-  Color get color => new Color.fromValue(const fb.Uint8Reader().vTableGet(_bc, _bcOffset, 16, 8));
-  AnyTypeId get testType => new AnyTypeId.fromValue(const fb.Uint8Reader().vTableGet(_bc, _bcOffset, 18, 0));
-  dynamic get test {
+  String? get name => const fb.StringReader().vTableGetNullable(_bc, _bcOffset, 10);
+  List<int>? get inventory => const fb.ListReader<int>(const fb.Uint8Reader()).vTableGetNullable(_bc, _bcOffset, 14);
+  Color get color => Color.fromValue(const fb.Uint8Reader().vTableGet(_bc, _bcOffset, 16, 8));
+  AnyTypeId? get testType => AnyTypeId._createOrNull(const fb.Uint8Reader().vTableGetNullable(_bc, _bcOffset, 18));
+  dynamic? get test {
     switch (testType?.value) {
-      case 1: return Monster.reader.vTableGet(_bc, _bcOffset, 20, null);
-      case 2: return TestSimpleTableWithEnum.reader.vTableGet(_bc, _bcOffset, 20, null);
-      case 3: return my_game_example2.Monster.reader.vTableGet(_bc, _bcOffset, 20, null);
+      case 1: return Monster.reader.vTableGetNullable(_bc, _bcOffset, 20);
+      case 2: return TestSimpleTableWithEnum.reader.vTableGetNullable(_bc, _bcOffset, 20);
+      case 3: return my_game_example2.Monster.reader.vTableGetNullable(_bc, _bcOffset, 20);
       default: return null;
     }
   }
-  List<Test> get test4 => const fb.ListReader<Test>(Test.reader).vTableGet(_bc, _bcOffset, 22, null);
-  List<String> get testarrayofstring => const fb.ListReader<String>(const fb.StringReader()).vTableGet(_bc, _bcOffset, 24, null);
+  List<Test>? get test4 => const fb.ListReader<Test>(Test.reader).vTableGetNullable(_bc, _bcOffset, 22);
+  List<String>? get testarrayofstring => const fb.ListReader<String>(const fb.StringReader()).vTableGetNullable(_bc, _bcOffset, 24);
   ///  an example documentation comment: this will end up in the generated code
   ///  multiline too
-  List<Monster> get testarrayoftables => const fb.ListReader<Monster>(Monster.reader).vTableGet(_bc, _bcOffset, 26, null);
-  Monster get enemy => Monster.reader.vTableGet(_bc, _bcOffset, 28, null);
-  List<int> get testnestedflatbuffer => const fb.ListReader<int>(const fb.Uint8Reader()).vTableGet(_bc, _bcOffset, 30, null);
-  Stat get testempty => Stat.reader.vTableGet(_bc, _bcOffset, 32, null);
+  List<Monster>? get testarrayoftables => const fb.ListReader<Monster>(Monster.reader).vTableGetNullable(_bc, _bcOffset, 26);
+  Monster? get enemy => Monster.reader.vTableGetNullable(_bc, _bcOffset, 28);
+  List<int>? get testnestedflatbuffer => const fb.ListReader<int>(const fb.Uint8Reader()).vTableGetNullable(_bc, _bcOffset, 30);
+  Stat? get testempty => Stat.reader.vTableGetNullable(_bc, _bcOffset, 32);
   bool get testbool => const fb.BoolReader().vTableGet(_bc, _bcOffset, 34, false);
   int get testhashs32Fnv1 => const fb.Int32Reader().vTableGet(_bc, _bcOffset, 36, 0);
   int get testhashu32Fnv1 => const fb.Uint32Reader().vTableGet(_bc, _bcOffset, 38, 0);
@@ -1084,47 +1065,47 @@ class Monster {
   int get testhashu32Fnv1a => const fb.Uint32Reader().vTableGet(_bc, _bcOffset, 46, 0);
   int get testhashs64Fnv1a => const fb.Int64Reader().vTableGet(_bc, _bcOffset, 48, 0);
   int get testhashu64Fnv1a => const fb.Uint64Reader().vTableGet(_bc, _bcOffset, 50, 0);
-  List<bool> get testarrayofbools => const fb.ListReader<bool>(const fb.BoolReader()).vTableGet(_bc, _bcOffset, 52, null);
+  List<bool>? get testarrayofbools => const fb.ListReader<bool>(const fb.BoolReader()).vTableGetNullable(_bc, _bcOffset, 52);
   double get testf => const fb.Float32Reader().vTableGet(_bc, _bcOffset, 54, 3.14159);
   double get testf2 => const fb.Float32Reader().vTableGet(_bc, _bcOffset, 56, 3.0);
   double get testf3 => const fb.Float32Reader().vTableGet(_bc, _bcOffset, 58, 0.0);
-  List<String> get testarrayofstring2 => const fb.ListReader<String>(const fb.StringReader()).vTableGet(_bc, _bcOffset, 60, null);
-  List<Ability> get testarrayofsortedstruct => const fb.ListReader<Ability>(Ability.reader).vTableGet(_bc, _bcOffset, 62, null);
-  List<int> get flex => const fb.ListReader<int>(const fb.Uint8Reader()).vTableGet(_bc, _bcOffset, 64, null);
-  List<Test> get test5 => const fb.ListReader<Test>(Test.reader).vTableGet(_bc, _bcOffset, 66, null);
-  List<int> get vectorOfLongs => const fb.ListReader<int>(const fb.Int64Reader()).vTableGet(_bc, _bcOffset, 68, null);
-  List<double> get vectorOfDoubles => const fb.ListReader<double>(const fb.Float64Reader()).vTableGet(_bc, _bcOffset, 70, null);
-  my_game.InParentNamespace get parentNamespaceTest => my_game.InParentNamespace.reader.vTableGet(_bc, _bcOffset, 72, null);
-  List<Referrable> get vectorOfReferrables => const fb.ListReader<Referrable>(Referrable.reader).vTableGet(_bc, _bcOffset, 74, null);
+  List<String>? get testarrayofstring2 => const fb.ListReader<String>(const fb.StringReader()).vTableGetNullable(_bc, _bcOffset, 60);
+  List<Ability>? get testarrayofsortedstruct => const fb.ListReader<Ability>(Ability.reader).vTableGetNullable(_bc, _bcOffset, 62);
+  List<int>? get flex => const fb.ListReader<int>(const fb.Uint8Reader()).vTableGetNullable(_bc, _bcOffset, 64);
+  List<Test>? get test5 => const fb.ListReader<Test>(Test.reader).vTableGetNullable(_bc, _bcOffset, 66);
+  List<int>? get vectorOfLongs => const fb.ListReader<int>(const fb.Int64Reader()).vTableGetNullable(_bc, _bcOffset, 68);
+  List<double>? get vectorOfDoubles => const fb.ListReader<double>(const fb.Float64Reader()).vTableGetNullable(_bc, _bcOffset, 70);
+  my_game.InParentNamespace? get parentNamespaceTest => my_game.InParentNamespace.reader.vTableGetNullable(_bc, _bcOffset, 72);
+  List<Referrable>? get vectorOfReferrables => const fb.ListReader<Referrable>(Referrable.reader).vTableGetNullable(_bc, _bcOffset, 74);
   int get singleWeakReference => const fb.Uint64Reader().vTableGet(_bc, _bcOffset, 76, 0);
-  List<int> get vectorOfWeakReferences => const fb.ListReader<int>(const fb.Uint64Reader()).vTableGet(_bc, _bcOffset, 78, null);
-  List<Referrable> get vectorOfStrongReferrables => const fb.ListReader<Referrable>(Referrable.reader).vTableGet(_bc, _bcOffset, 80, null);
+  List<int>? get vectorOfWeakReferences => const fb.ListReader<int>(const fb.Uint64Reader()).vTableGetNullable(_bc, _bcOffset, 78);
+  List<Referrable>? get vectorOfStrongReferrables => const fb.ListReader<Referrable>(Referrable.reader).vTableGetNullable(_bc, _bcOffset, 80);
   int get coOwningReference => const fb.Uint64Reader().vTableGet(_bc, _bcOffset, 82, 0);
-  List<int> get vectorOfCoOwningReferences => const fb.ListReader<int>(const fb.Uint64Reader()).vTableGet(_bc, _bcOffset, 84, null);
+  List<int>? get vectorOfCoOwningReferences => const fb.ListReader<int>(const fb.Uint64Reader()).vTableGetNullable(_bc, _bcOffset, 84);
   int get nonOwningReference => const fb.Uint64Reader().vTableGet(_bc, _bcOffset, 86, 0);
-  List<int> get vectorOfNonOwningReferences => const fb.ListReader<int>(const fb.Uint64Reader()).vTableGet(_bc, _bcOffset, 88, null);
-  AnyUniqueAliasesTypeId get anyUniqueType => new AnyUniqueAliasesTypeId.fromValue(const fb.Uint8Reader().vTableGet(_bc, _bcOffset, 90, 0));
-  dynamic get anyUnique {
+  List<int>? get vectorOfNonOwningReferences => const fb.ListReader<int>(const fb.Uint64Reader()).vTableGetNullable(_bc, _bcOffset, 88);
+  AnyUniqueAliasesTypeId? get anyUniqueType => AnyUniqueAliasesTypeId._createOrNull(const fb.Uint8Reader().vTableGetNullable(_bc, _bcOffset, 90));
+  dynamic? get anyUnique {
     switch (anyUniqueType?.value) {
-      case 1: return Monster.reader.vTableGet(_bc, _bcOffset, 92, null);
-      case 2: return TestSimpleTableWithEnum.reader.vTableGet(_bc, _bcOffset, 92, null);
-      case 3: return my_game_example2.Monster.reader.vTableGet(_bc, _bcOffset, 92, null);
+      case 1: return Monster.reader.vTableGetNullable(_bc, _bcOffset, 92);
+      case 2: return TestSimpleTableWithEnum.reader.vTableGetNullable(_bc, _bcOffset, 92);
+      case 3: return my_game_example2.Monster.reader.vTableGetNullable(_bc, _bcOffset, 92);
       default: return null;
     }
   }
-  AnyAmbiguousAliasesTypeId get anyAmbiguousType => new AnyAmbiguousAliasesTypeId.fromValue(const fb.Uint8Reader().vTableGet(_bc, _bcOffset, 94, 0));
-  dynamic get anyAmbiguous {
+  AnyAmbiguousAliasesTypeId? get anyAmbiguousType => AnyAmbiguousAliasesTypeId._createOrNull(const fb.Uint8Reader().vTableGetNullable(_bc, _bcOffset, 94));
+  dynamic? get anyAmbiguous {
     switch (anyAmbiguousType?.value) {
-      case 1: return Monster.reader.vTableGet(_bc, _bcOffset, 96, null);
-      case 2: return Monster.reader.vTableGet(_bc, _bcOffset, 96, null);
-      case 3: return Monster.reader.vTableGet(_bc, _bcOffset, 96, null);
+      case 1: return Monster.reader.vTableGetNullable(_bc, _bcOffset, 96);
+      case 2: return Monster.reader.vTableGetNullable(_bc, _bcOffset, 96);
+      case 3: return Monster.reader.vTableGetNullable(_bc, _bcOffset, 96);
       default: return null;
     }
   }
-  List<Color> get vectorOfEnums => const fb.ListReader<Color>(Color.reader).vTableGet(_bc, _bcOffset, 98, null);
-  Race get signedEnum => new Race.fromValue(const fb.Int8Reader().vTableGet(_bc, _bcOffset, 100, -1));
-  List<int> get testrequirednestedflatbuffer => const fb.ListReader<int>(const fb.Uint8Reader()).vTableGet(_bc, _bcOffset, 102, null);
-  List<Stat> get scalarKeySortedTables => const fb.ListReader<Stat>(Stat.reader).vTableGet(_bc, _bcOffset, 104, null);
+  List<Color>? get vectorOfEnums => const fb.ListReader<Color>(Color.reader).vTableGetNullable(_bc, _bcOffset, 98);
+  Race get signedEnum => Race.fromValue(const fb.Int8Reader().vTableGet(_bc, _bcOffset, 100, -1));
+  List<int>? get testrequirednestedflatbuffer => const fb.ListReader<int>(const fb.Uint8Reader()).vTableGetNullable(_bc, _bcOffset, 102);
+  List<Stat>? get scalarKeySortedTables => const fb.ListReader<Stat>(Stat.reader).vTableGetNullable(_bc, _bcOffset, 104);
 
   @override
   String toString() {
@@ -1140,9 +1121,9 @@ class Monster {
       color: color,
       testType: testType,
       test: test,
-      test4: test4?.map((e) => e.unpack())?.toList(),
+      test4: test4?.map((e) => e.unpack()).toList(),
       testarrayofstring: testarrayofstring,
-      testarrayoftables: testarrayoftables?.map((e) => e.unpack())?.toList(),
+      testarrayoftables: testarrayoftables?.map((e) => e.unpack()).toList(),
       enemy: enemy?.unpack(),
       testnestedflatbuffer: testnestedflatbuffer,
       testempty: testempty?.unpack(),
@@ -1160,16 +1141,16 @@ class Monster {
       testf2: testf2,
       testf3: testf3,
       testarrayofstring2: testarrayofstring2,
-      testarrayofsortedstruct: testarrayofsortedstruct?.map((e) => e.unpack())?.toList(),
+      testarrayofsortedstruct: testarrayofsortedstruct?.map((e) => e.unpack()).toList(),
       flex: flex,
-      test5: test5?.map((e) => e.unpack())?.toList(),
+      test5: test5?.map((e) => e.unpack()).toList(),
       vectorOfLongs: vectorOfLongs,
       vectorOfDoubles: vectorOfDoubles,
       parentNamespaceTest: parentNamespaceTest?.unpack(),
-      vectorOfReferrables: vectorOfReferrables?.map((e) => e.unpack())?.toList(),
+      vectorOfReferrables: vectorOfReferrables?.map((e) => e.unpack()).toList(),
       singleWeakReference: singleWeakReference,
       vectorOfWeakReferences: vectorOfWeakReferences,
-      vectorOfStrongReferrables: vectorOfStrongReferrables?.map((e) => e.unpack())?.toList(),
+      vectorOfStrongReferrables: vectorOfStrongReferrables?.map((e) => e.unpack()).toList(),
       coOwningReference: coOwningReference,
       vectorOfCoOwningReferences: vectorOfCoOwningReferences,
       nonOwningReference: nonOwningReference,
@@ -1181,9 +1162,9 @@ class Monster {
       vectorOfEnums: vectorOfEnums,
       signedEnum: signedEnum,
       testrequirednestedflatbuffer: testrequirednestedflatbuffer,
-      scalarKeySortedTables: scalarKeySortedTables?.map((e) => e.unpack())?.toList());
+      scalarKeySortedTables: scalarKeySortedTables?.map((e) => e.unpack()).toList());
 
-  static int pack(fb.Builder fbBuilder, MonsterT object) {
+  static int pack(fb.Builder fbBuilder, MonsterT? object) {
     if (object == null) return 0;
     return object.pack(fbBuilder);
   }
@@ -1191,22 +1172,22 @@ class Monster {
 
 ///  an example documentation comment: "monster object"
 class MonsterT {
-  Vec3T pos;
+  Vec3T? pos;
   int mana;
   int hp;
-  String name;
-  List<int> inventory;
+  String? name;
+  List<int>? inventory;
   Color color;
-  AnyTypeId testType;
-  dynamic test;
-  List<TestT> test4;
-  List<String> testarrayofstring;
+  AnyTypeId? testType;
+  dynamic? test;
+  List<TestT>? test4;
+  List<String>? testarrayofstring;
   ///  an example documentation comment: this will end up in the generated code
   ///  multiline too
-  List<MonsterT> testarrayoftables;
-  MonsterT enemy;
-  List<int> testnestedflatbuffer;
-  StatT testempty;
+  List<MonsterT>? testarrayoftables;
+  MonsterT? enemy;
+  List<int>? testnestedflatbuffer;
+  StatT? testempty;
   bool testbool;
   int testhashs32Fnv1;
   int testhashu32Fnv1;
@@ -1216,41 +1197,41 @@ class MonsterT {
   int testhashu32Fnv1a;
   int testhashs64Fnv1a;
   int testhashu64Fnv1a;
-  List<bool> testarrayofbools;
+  List<bool>? testarrayofbools;
   double testf;
   double testf2;
   double testf3;
-  List<String> testarrayofstring2;
-  List<AbilityT> testarrayofsortedstruct;
-  List<int> flex;
-  List<TestT> test5;
-  List<int> vectorOfLongs;
-  List<double> vectorOfDoubles;
-  my_game.InParentNamespaceT parentNamespaceTest;
-  List<ReferrableT> vectorOfReferrables;
+  List<String>? testarrayofstring2;
+  List<AbilityT>? testarrayofsortedstruct;
+  List<int>? flex;
+  List<TestT>? test5;
+  List<int>? vectorOfLongs;
+  List<double>? vectorOfDoubles;
+  my_game.InParentNamespaceT? parentNamespaceTest;
+  List<ReferrableT>? vectorOfReferrables;
   int singleWeakReference;
-  List<int> vectorOfWeakReferences;
-  List<ReferrableT> vectorOfStrongReferrables;
+  List<int>? vectorOfWeakReferences;
+  List<ReferrableT>? vectorOfStrongReferrables;
   int coOwningReference;
-  List<int> vectorOfCoOwningReferences;
+  List<int>? vectorOfCoOwningReferences;
   int nonOwningReference;
-  List<int> vectorOfNonOwningReferences;
-  AnyUniqueAliasesTypeId anyUniqueType;
-  dynamic anyUnique;
-  AnyAmbiguousAliasesTypeId anyAmbiguousType;
-  dynamic anyAmbiguous;
-  List<Color> vectorOfEnums;
+  List<int>? vectorOfNonOwningReferences;
+  AnyUniqueAliasesTypeId? anyUniqueType;
+  dynamic? anyUnique;
+  AnyAmbiguousAliasesTypeId? anyAmbiguousType;
+  dynamic? anyAmbiguous;
+  List<Color>? vectorOfEnums;
   Race signedEnum;
-  List<int> testrequirednestedflatbuffer;
-  List<StatT> scalarKeySortedTables;
+  List<int>? testrequirednestedflatbuffer;
+  List<StatT>? scalarKeySortedTables;
 
   MonsterT({
       this.pos,
-      this.mana,
-      this.hp,
+      this.mana = 150,
+      this.hp = 100,
       this.name,
       this.inventory,
-      this.color,
+      this.color = Color.Blue,
       this.testType,
       this.test,
       this.test4,
@@ -1259,19 +1240,19 @@ class MonsterT {
       this.enemy,
       this.testnestedflatbuffer,
       this.testempty,
-      this.testbool,
-      this.testhashs32Fnv1,
-      this.testhashu32Fnv1,
-      this.testhashs64Fnv1,
-      this.testhashu64Fnv1,
-      this.testhashs32Fnv1a,
-      this.testhashu32Fnv1a,
-      this.testhashs64Fnv1a,
-      this.testhashu64Fnv1a,
+      this.testbool = false,
+      this.testhashs32Fnv1 = 0,
+      this.testhashu32Fnv1 = 0,
+      this.testhashs64Fnv1 = 0,
+      this.testhashu64Fnv1 = 0,
+      this.testhashs32Fnv1a = 0,
+      this.testhashu32Fnv1a = 0,
+      this.testhashs64Fnv1a = 0,
+      this.testhashu64Fnv1a = 0,
       this.testarrayofbools,
-      this.testf,
-      this.testf2,
-      this.testf3,
+      this.testf = 3.14159,
+      this.testf2 = 3.0,
+      this.testf3 = 0.0,
       this.testarrayofstring2,
       this.testarrayofsortedstruct,
       this.flex,
@@ -1280,133 +1261,113 @@ class MonsterT {
       this.vectorOfDoubles,
       this.parentNamespaceTest,
       this.vectorOfReferrables,
-      this.singleWeakReference,
+      this.singleWeakReference = 0,
       this.vectorOfWeakReferences,
       this.vectorOfStrongReferrables,
-      this.coOwningReference,
+      this.coOwningReference = 0,
       this.vectorOfCoOwningReferences,
-      this.nonOwningReference,
+      this.nonOwningReference = 0,
       this.vectorOfNonOwningReferences,
       this.anyUniqueType,
       this.anyUnique,
       this.anyAmbiguousType,
       this.anyAmbiguous,
       this.vectorOfEnums,
-      this.signedEnum,
+      this.signedEnum = Race.None,
       this.testrequirednestedflatbuffer,
       this.scalarKeySortedTables});
 
   int pack(fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-    final int nameOffset = fbBuilder.writeString(name);
-    final int inventoryOffset = inventory?.isNotEmpty == true
-        ? fbBuilder.writeListUint8(inventory)
+    final int? nameOffset = fbBuilder.writeString(name);
+    final int? inventoryOffset = inventory?.isNotEmpty == true
+        ? fbBuilder.writeListUint8(inventory!)
         : null;
-    final int testOffset = test?.pack(fbBuilder);
-    int test4Offset = null;
+    final int? testOffset = test?.pack(fbBuilder);
+    int? test4Offset = null;
     if (test4?.isNotEmpty == true) {
-      test4.forEach((e) => e.pack(fbBuilder));
-      test4Offset = fbBuilder.endStructVector(test4.length);
+      test4!.forEach((e) => e.pack(fbBuilder));
+      test4Offset = fbBuilder.endStructVector(test4!.length);
     }
-    final int testarrayofstringOffset = testarrayofstring?.isNotEmpty == true
-        ? fbBuilder.writeList(testarrayofstring.map((b) => fbBuilder.writeString(b)).toList())
+    final int? testarrayofstringOffset = testarrayofstring?.isNotEmpty == true
+        ? fbBuilder.writeList(testarrayofstring!.map((b) => fbBuilder.writeString(b)!).toList())
         : null;
-    final int testarrayoftablesOffset = testarrayoftables?.isNotEmpty == true
-        ? fbBuilder.writeList(testarrayoftables.map((b) => b.pack(fbBuilder)).toList())
+    final int? testarrayoftablesOffset = testarrayoftables?.isNotEmpty == true
+        ? fbBuilder.writeList(testarrayoftables!.map((b) => b.pack(fbBuilder)).toList())
         : null;
-    final int enemyOffset = enemy?.pack(fbBuilder);
-    final int testnestedflatbufferOffset = testnestedflatbuffer?.isNotEmpty == true
-        ? fbBuilder.writeListUint8(testnestedflatbuffer)
+    final int? enemyOffset = enemy?.pack(fbBuilder);
+    final int? testnestedflatbufferOffset = testnestedflatbuffer?.isNotEmpty == true
+        ? fbBuilder.writeListUint8(testnestedflatbuffer!)
         : null;
-    final int testemptyOffset = testempty?.pack(fbBuilder);
-    final int testarrayofboolsOffset = testarrayofbools?.isNotEmpty == true
-        ? fbBuilder.writeListBool(testarrayofbools)
+    final int? testemptyOffset = testempty?.pack(fbBuilder);
+    final int? testarrayofboolsOffset = testarrayofbools?.isNotEmpty == true
+        ? fbBuilder.writeListBool(testarrayofbools!)
         : null;
-    final int testarrayofstring2Offset = testarrayofstring2?.isNotEmpty == true
-        ? fbBuilder.writeList(testarrayofstring2.map((b) => fbBuilder.writeString(b)).toList())
+    final int? testarrayofstring2Offset = testarrayofstring2?.isNotEmpty == true
+        ? fbBuilder.writeList(testarrayofstring2!.map((b) => fbBuilder.writeString(b)!).toList())
         : null;
-    int testarrayofsortedstructOffset = null;
+    int? testarrayofsortedstructOffset = null;
     if (testarrayofsortedstruct?.isNotEmpty == true) {
-      testarrayofsortedstruct.forEach((e) => e.pack(fbBuilder));
-      testarrayofsortedstructOffset = fbBuilder.endStructVector(testarrayofsortedstruct.length);
+      testarrayofsortedstruct!.forEach((e) => e.pack(fbBuilder));
+      testarrayofsortedstructOffset = fbBuilder.endStructVector(testarrayofsortedstruct!.length);
     }
-    final int flexOffset = flex?.isNotEmpty == true
-        ? fbBuilder.writeListUint8(flex)
+    final int? flexOffset = flex?.isNotEmpty == true
+        ? fbBuilder.writeListUint8(flex!)
         : null;
-    int test5Offset = null;
+    int? test5Offset = null;
     if (test5?.isNotEmpty == true) {
-      test5.forEach((e) => e.pack(fbBuilder));
-      test5Offset = fbBuilder.endStructVector(test5.length);
+      test5!.forEach((e) => e.pack(fbBuilder));
+      test5Offset = fbBuilder.endStructVector(test5!.length);
     }
-    final int vectorOfLongsOffset = vectorOfLongs?.isNotEmpty == true
-        ? fbBuilder.writeListInt64(vectorOfLongs)
+    final int? vectorOfLongsOffset = vectorOfLongs?.isNotEmpty == true
+        ? fbBuilder.writeListInt64(vectorOfLongs!)
         : null;
-    final int vectorOfDoublesOffset = vectorOfDoubles?.isNotEmpty == true
-        ? fbBuilder.writeListFloat64(vectorOfDoubles)
+    final int? vectorOfDoublesOffset = vectorOfDoubles?.isNotEmpty == true
+        ? fbBuilder.writeListFloat64(vectorOfDoubles!)
         : null;
-    final int parentNamespaceTestOffset = parentNamespaceTest?.pack(fbBuilder);
-    final int vectorOfReferrablesOffset = vectorOfReferrables?.isNotEmpty == true
-        ? fbBuilder.writeList(vectorOfReferrables.map((b) => b.pack(fbBuilder)).toList())
+    final int? parentNamespaceTestOffset = parentNamespaceTest?.pack(fbBuilder);
+    final int? vectorOfReferrablesOffset = vectorOfReferrables?.isNotEmpty == true
+        ? fbBuilder.writeList(vectorOfReferrables!.map((b) => b.pack(fbBuilder)).toList())
         : null;
-    final int vectorOfWeakReferencesOffset = vectorOfWeakReferences?.isNotEmpty == true
-        ? fbBuilder.writeListUint64(vectorOfWeakReferences)
+    final int? vectorOfWeakReferencesOffset = vectorOfWeakReferences?.isNotEmpty == true
+        ? fbBuilder.writeListUint64(vectorOfWeakReferences!)
         : null;
-    final int vectorOfStrongReferrablesOffset = vectorOfStrongReferrables?.isNotEmpty == true
-        ? fbBuilder.writeList(vectorOfStrongReferrables.map((b) => b.pack(fbBuilder)).toList())
+    final int? vectorOfStrongReferrablesOffset = vectorOfStrongReferrables?.isNotEmpty == true
+        ? fbBuilder.writeList(vectorOfStrongReferrables!.map((b) => b.pack(fbBuilder)).toList())
         : null;
-    final int vectorOfCoOwningReferencesOffset = vectorOfCoOwningReferences?.isNotEmpty == true
-        ? fbBuilder.writeListUint64(vectorOfCoOwningReferences)
+    final int? vectorOfCoOwningReferencesOffset = vectorOfCoOwningReferences?.isNotEmpty == true
+        ? fbBuilder.writeListUint64(vectorOfCoOwningReferences!)
         : null;
-    final int vectorOfNonOwningReferencesOffset = vectorOfNonOwningReferences?.isNotEmpty == true
-        ? fbBuilder.writeListUint64(vectorOfNonOwningReferences)
+    final int? vectorOfNonOwningReferencesOffset = vectorOfNonOwningReferences?.isNotEmpty == true
+        ? fbBuilder.writeListUint64(vectorOfNonOwningReferences!)
         : null;
-    final int anyUniqueOffset = anyUnique?.pack(fbBuilder);
-    final int anyAmbiguousOffset = anyAmbiguous?.pack(fbBuilder);
-    final int vectorOfEnumsOffset = vectorOfEnums?.isNotEmpty == true
-        ? fbBuilder.writeListUint8(vectorOfEnums.map((f) => f.value).toList())
+    final int? anyUniqueOffset = anyUnique?.pack(fbBuilder);
+    final int? anyAmbiguousOffset = anyAmbiguous?.pack(fbBuilder);
+    final int? vectorOfEnumsOffset = vectorOfEnums?.isNotEmpty == true
+        ? fbBuilder.writeListUint8(vectorOfEnums!.map((f) => f.value).toList())
         : null;
-    final int testrequirednestedflatbufferOffset = testrequirednestedflatbuffer?.isNotEmpty == true
-        ? fbBuilder.writeListUint8(testrequirednestedflatbuffer)
+    final int? testrequirednestedflatbufferOffset = testrequirednestedflatbuffer?.isNotEmpty == true
+        ? fbBuilder.writeListUint8(testrequirednestedflatbuffer!)
         : null;
-    final int scalarKeySortedTablesOffset = scalarKeySortedTables?.isNotEmpty == true
-        ? fbBuilder.writeList(scalarKeySortedTables.map((b) => b.pack(fbBuilder)).toList())
+    final int? scalarKeySortedTablesOffset = scalarKeySortedTables?.isNotEmpty == true
+        ? fbBuilder.writeList(scalarKeySortedTables!.map((b) => b.pack(fbBuilder)).toList())
         : null;
-
     fbBuilder.startTable();
     if (pos != null) {
-      fbBuilder.addStruct(0, pos.pack(fbBuilder));
+      fbBuilder.addStruct(0, pos!.pack(fbBuilder));
     }
     fbBuilder.addInt16(1, mana);
     fbBuilder.addInt16(2, hp);
-    if (nameOffset != null) {
-      fbBuilder.addOffset(3, nameOffset);
-    }
-    if (inventoryOffset != null) {
-      fbBuilder.addOffset(5, inventoryOffset);
-    }
-    fbBuilder.addUint8(6, color?.value);
+    fbBuilder.addOffset(3, nameOffset);
+    fbBuilder.addOffset(5, inventoryOffset);
+    fbBuilder.addUint8(6, color.value);
     fbBuilder.addUint8(7, testType?.value);
-    if (testOffset != null) {
-      fbBuilder.addOffset(8, testOffset);
-    }
-    if (test4Offset != null) {
-      fbBuilder.addOffset(9, test4Offset);
-    }
-    if (testarrayofstringOffset != null) {
-      fbBuilder.addOffset(10, testarrayofstringOffset);
-    }
-    if (testarrayoftablesOffset != null) {
-      fbBuilder.addOffset(11, testarrayoftablesOffset);
-    }
-    if (enemyOffset != null) {
-      fbBuilder.addOffset(12, enemyOffset);
-    }
-    if (testnestedflatbufferOffset != null) {
-      fbBuilder.addOffset(13, testnestedflatbufferOffset);
-    }
-    if (testemptyOffset != null) {
-      fbBuilder.addOffset(14, testemptyOffset);
-    }
+    fbBuilder.addOffset(8, testOffset);
+    fbBuilder.addOffset(9, test4Offset);
+    fbBuilder.addOffset(10, testarrayofstringOffset);
+    fbBuilder.addOffset(11, testarrayoftablesOffset);
+    fbBuilder.addOffset(12, enemyOffset);
+    fbBuilder.addOffset(13, testnestedflatbufferOffset);
+    fbBuilder.addOffset(14, testemptyOffset);
     fbBuilder.addBool(15, testbool);
     fbBuilder.addInt32(16, testhashs32Fnv1);
     fbBuilder.addUint32(17, testhashu32Fnv1);
@@ -1416,69 +1377,33 @@ class MonsterT {
     fbBuilder.addUint32(21, testhashu32Fnv1a);
     fbBuilder.addInt64(22, testhashs64Fnv1a);
     fbBuilder.addUint64(23, testhashu64Fnv1a);
-    if (testarrayofboolsOffset != null) {
-      fbBuilder.addOffset(24, testarrayofboolsOffset);
-    }
+    fbBuilder.addOffset(24, testarrayofboolsOffset);
     fbBuilder.addFloat32(25, testf);
     fbBuilder.addFloat32(26, testf2);
     fbBuilder.addFloat32(27, testf3);
-    if (testarrayofstring2Offset != null) {
-      fbBuilder.addOffset(28, testarrayofstring2Offset);
-    }
-    if (testarrayofsortedstructOffset != null) {
-      fbBuilder.addOffset(29, testarrayofsortedstructOffset);
-    }
-    if (flexOffset != null) {
-      fbBuilder.addOffset(30, flexOffset);
-    }
-    if (test5Offset != null) {
-      fbBuilder.addOffset(31, test5Offset);
-    }
-    if (vectorOfLongsOffset != null) {
-      fbBuilder.addOffset(32, vectorOfLongsOffset);
-    }
-    if (vectorOfDoublesOffset != null) {
-      fbBuilder.addOffset(33, vectorOfDoublesOffset);
-    }
-    if (parentNamespaceTestOffset != null) {
-      fbBuilder.addOffset(34, parentNamespaceTestOffset);
-    }
-    if (vectorOfReferrablesOffset != null) {
-      fbBuilder.addOffset(35, vectorOfReferrablesOffset);
-    }
+    fbBuilder.addOffset(28, testarrayofstring2Offset);
+    fbBuilder.addOffset(29, testarrayofsortedstructOffset);
+    fbBuilder.addOffset(30, flexOffset);
+    fbBuilder.addOffset(31, test5Offset);
+    fbBuilder.addOffset(32, vectorOfLongsOffset);
+    fbBuilder.addOffset(33, vectorOfDoublesOffset);
+    fbBuilder.addOffset(34, parentNamespaceTestOffset);
+    fbBuilder.addOffset(35, vectorOfReferrablesOffset);
     fbBuilder.addUint64(36, singleWeakReference);
-    if (vectorOfWeakReferencesOffset != null) {
-      fbBuilder.addOffset(37, vectorOfWeakReferencesOffset);
-    }
-    if (vectorOfStrongReferrablesOffset != null) {
-      fbBuilder.addOffset(38, vectorOfStrongReferrablesOffset);
-    }
+    fbBuilder.addOffset(37, vectorOfWeakReferencesOffset);
+    fbBuilder.addOffset(38, vectorOfStrongReferrablesOffset);
     fbBuilder.addUint64(39, coOwningReference);
-    if (vectorOfCoOwningReferencesOffset != null) {
-      fbBuilder.addOffset(40, vectorOfCoOwningReferencesOffset);
-    }
+    fbBuilder.addOffset(40, vectorOfCoOwningReferencesOffset);
     fbBuilder.addUint64(41, nonOwningReference);
-    if (vectorOfNonOwningReferencesOffset != null) {
-      fbBuilder.addOffset(42, vectorOfNonOwningReferencesOffset);
-    }
+    fbBuilder.addOffset(42, vectorOfNonOwningReferencesOffset);
     fbBuilder.addUint8(43, anyUniqueType?.value);
-    if (anyUniqueOffset != null) {
-      fbBuilder.addOffset(44, anyUniqueOffset);
-    }
+    fbBuilder.addOffset(44, anyUniqueOffset);
     fbBuilder.addUint8(45, anyAmbiguousType?.value);
-    if (anyAmbiguousOffset != null) {
-      fbBuilder.addOffset(46, anyAmbiguousOffset);
-    }
-    if (vectorOfEnumsOffset != null) {
-      fbBuilder.addOffset(47, vectorOfEnumsOffset);
-    }
-    fbBuilder.addInt8(48, signedEnum?.value);
-    if (testrequirednestedflatbufferOffset != null) {
-      fbBuilder.addOffset(49, testrequirednestedflatbufferOffset);
-    }
-    if (scalarKeySortedTablesOffset != null) {
-      fbBuilder.addOffset(50, scalarKeySortedTablesOffset);
-    }
+    fbBuilder.addOffset(46, anyAmbiguousOffset);
+    fbBuilder.addOffset(47, vectorOfEnumsOffset);
+    fbBuilder.addInt8(48, signedEnum.value);
+    fbBuilder.addOffset(49, testrequirednestedflatbufferOffset);
+    fbBuilder.addOffset(50, scalarKeySortedTablesOffset);
     return fbBuilder.endTable();
   }
 
@@ -1497,9 +1422,7 @@ class _MonsterReader extends fb.TableReader<Monster> {
 }
 
 class MonsterBuilder {
-  MonsterBuilder(this.fbBuilder) {
-    assert(fbBuilder != null);
-  }
+  MonsterBuilder(this.fbBuilder) {}
 
   final fb.Builder fbBuilder;
 
@@ -1511,199 +1434,199 @@ class MonsterBuilder {
     fbBuilder.addStruct(0, offset);
     return fbBuilder.offset;
   }
-  int addMana(int mana) {
+  int addMana(int? mana) {
     fbBuilder.addInt16(1, mana);
     return fbBuilder.offset;
   }
-  int addHp(int hp) {
+  int addHp(int? hp) {
     fbBuilder.addInt16(2, hp);
     return fbBuilder.offset;
   }
-  int addNameOffset(int offset) {
+  int addNameOffset(int? offset) {
     fbBuilder.addOffset(3, offset);
     return fbBuilder.offset;
   }
-  int addInventoryOffset(int offset) {
+  int addInventoryOffset(int? offset) {
     fbBuilder.addOffset(5, offset);
     return fbBuilder.offset;
   }
-  int addColor(Color color) {
+  int addColor(Color? color) {
     fbBuilder.addUint8(6, color?.value);
     return fbBuilder.offset;
   }
-  int addTestType(AnyTypeId testType) {
+  int addTestType(AnyTypeId? testType) {
     fbBuilder.addUint8(7, testType?.value);
     return fbBuilder.offset;
   }
-  int addTestOffset(int offset) {
+  int addTestOffset(int? offset) {
     fbBuilder.addOffset(8, offset);
     return fbBuilder.offset;
   }
-  int addTest4Offset(int offset) {
+  int addTest4Offset(int? offset) {
     fbBuilder.addOffset(9, offset);
     return fbBuilder.offset;
   }
-  int addTestarrayofstringOffset(int offset) {
+  int addTestarrayofstringOffset(int? offset) {
     fbBuilder.addOffset(10, offset);
     return fbBuilder.offset;
   }
-  int addTestarrayoftablesOffset(int offset) {
+  int addTestarrayoftablesOffset(int? offset) {
     fbBuilder.addOffset(11, offset);
     return fbBuilder.offset;
   }
-  int addEnemyOffset(int offset) {
+  int addEnemyOffset(int? offset) {
     fbBuilder.addOffset(12, offset);
     return fbBuilder.offset;
   }
-  int addTestnestedflatbufferOffset(int offset) {
+  int addTestnestedflatbufferOffset(int? offset) {
     fbBuilder.addOffset(13, offset);
     return fbBuilder.offset;
   }
-  int addTestemptyOffset(int offset) {
+  int addTestemptyOffset(int? offset) {
     fbBuilder.addOffset(14, offset);
     return fbBuilder.offset;
   }
-  int addTestbool(bool testbool) {
+  int addTestbool(bool? testbool) {
     fbBuilder.addBool(15, testbool);
     return fbBuilder.offset;
   }
-  int addTesthashs32Fnv1(int testhashs32Fnv1) {
+  int addTesthashs32Fnv1(int? testhashs32Fnv1) {
     fbBuilder.addInt32(16, testhashs32Fnv1);
     return fbBuilder.offset;
   }
-  int addTesthashu32Fnv1(int testhashu32Fnv1) {
+  int addTesthashu32Fnv1(int? testhashu32Fnv1) {
     fbBuilder.addUint32(17, testhashu32Fnv1);
     return fbBuilder.offset;
   }
-  int addTesthashs64Fnv1(int testhashs64Fnv1) {
+  int addTesthashs64Fnv1(int? testhashs64Fnv1) {
     fbBuilder.addInt64(18, testhashs64Fnv1);
     return fbBuilder.offset;
   }
-  int addTesthashu64Fnv1(int testhashu64Fnv1) {
+  int addTesthashu64Fnv1(int? testhashu64Fnv1) {
     fbBuilder.addUint64(19, testhashu64Fnv1);
     return fbBuilder.offset;
   }
-  int addTesthashs32Fnv1a(int testhashs32Fnv1a) {
+  int addTesthashs32Fnv1a(int? testhashs32Fnv1a) {
     fbBuilder.addInt32(20, testhashs32Fnv1a);
     return fbBuilder.offset;
   }
-  int addTesthashu32Fnv1a(int testhashu32Fnv1a) {
+  int addTesthashu32Fnv1a(int? testhashu32Fnv1a) {
     fbBuilder.addUint32(21, testhashu32Fnv1a);
     return fbBuilder.offset;
   }
-  int addTesthashs64Fnv1a(int testhashs64Fnv1a) {
+  int addTesthashs64Fnv1a(int? testhashs64Fnv1a) {
     fbBuilder.addInt64(22, testhashs64Fnv1a);
     return fbBuilder.offset;
   }
-  int addTesthashu64Fnv1a(int testhashu64Fnv1a) {
+  int addTesthashu64Fnv1a(int? testhashu64Fnv1a) {
     fbBuilder.addUint64(23, testhashu64Fnv1a);
     return fbBuilder.offset;
   }
-  int addTestarrayofboolsOffset(int offset) {
+  int addTestarrayofboolsOffset(int? offset) {
     fbBuilder.addOffset(24, offset);
     return fbBuilder.offset;
   }
-  int addTestf(double testf) {
+  int addTestf(double? testf) {
     fbBuilder.addFloat32(25, testf);
     return fbBuilder.offset;
   }
-  int addTestf2(double testf2) {
+  int addTestf2(double? testf2) {
     fbBuilder.addFloat32(26, testf2);
     return fbBuilder.offset;
   }
-  int addTestf3(double testf3) {
+  int addTestf3(double? testf3) {
     fbBuilder.addFloat32(27, testf3);
     return fbBuilder.offset;
   }
-  int addTestarrayofstring2Offset(int offset) {
+  int addTestarrayofstring2Offset(int? offset) {
     fbBuilder.addOffset(28, offset);
     return fbBuilder.offset;
   }
-  int addTestarrayofsortedstructOffset(int offset) {
+  int addTestarrayofsortedstructOffset(int? offset) {
     fbBuilder.addOffset(29, offset);
     return fbBuilder.offset;
   }
-  int addFlexOffset(int offset) {
+  int addFlexOffset(int? offset) {
     fbBuilder.addOffset(30, offset);
     return fbBuilder.offset;
   }
-  int addTest5Offset(int offset) {
+  int addTest5Offset(int? offset) {
     fbBuilder.addOffset(31, offset);
     return fbBuilder.offset;
   }
-  int addVectorOfLongsOffset(int offset) {
+  int addVectorOfLongsOffset(int? offset) {
     fbBuilder.addOffset(32, offset);
     return fbBuilder.offset;
   }
-  int addVectorOfDoublesOffset(int offset) {
+  int addVectorOfDoublesOffset(int? offset) {
     fbBuilder.addOffset(33, offset);
     return fbBuilder.offset;
   }
-  int addParentNamespaceTestOffset(int offset) {
+  int addParentNamespaceTestOffset(int? offset) {
     fbBuilder.addOffset(34, offset);
     return fbBuilder.offset;
   }
-  int addVectorOfReferrablesOffset(int offset) {
+  int addVectorOfReferrablesOffset(int? offset) {
     fbBuilder.addOffset(35, offset);
     return fbBuilder.offset;
   }
-  int addSingleWeakReference(int singleWeakReference) {
+  int addSingleWeakReference(int? singleWeakReference) {
     fbBuilder.addUint64(36, singleWeakReference);
     return fbBuilder.offset;
   }
-  int addVectorOfWeakReferencesOffset(int offset) {
+  int addVectorOfWeakReferencesOffset(int? offset) {
     fbBuilder.addOffset(37, offset);
     return fbBuilder.offset;
   }
-  int addVectorOfStrongReferrablesOffset(int offset) {
+  int addVectorOfStrongReferrablesOffset(int? offset) {
     fbBuilder.addOffset(38, offset);
     return fbBuilder.offset;
   }
-  int addCoOwningReference(int coOwningReference) {
+  int addCoOwningReference(int? coOwningReference) {
     fbBuilder.addUint64(39, coOwningReference);
     return fbBuilder.offset;
   }
-  int addVectorOfCoOwningReferencesOffset(int offset) {
+  int addVectorOfCoOwningReferencesOffset(int? offset) {
     fbBuilder.addOffset(40, offset);
     return fbBuilder.offset;
   }
-  int addNonOwningReference(int nonOwningReference) {
+  int addNonOwningReference(int? nonOwningReference) {
     fbBuilder.addUint64(41, nonOwningReference);
     return fbBuilder.offset;
   }
-  int addVectorOfNonOwningReferencesOffset(int offset) {
+  int addVectorOfNonOwningReferencesOffset(int? offset) {
     fbBuilder.addOffset(42, offset);
     return fbBuilder.offset;
   }
-  int addAnyUniqueType(AnyUniqueAliasesTypeId anyUniqueType) {
+  int addAnyUniqueType(AnyUniqueAliasesTypeId? anyUniqueType) {
     fbBuilder.addUint8(43, anyUniqueType?.value);
     return fbBuilder.offset;
   }
-  int addAnyUniqueOffset(int offset) {
+  int addAnyUniqueOffset(int? offset) {
     fbBuilder.addOffset(44, offset);
     return fbBuilder.offset;
   }
-  int addAnyAmbiguousType(AnyAmbiguousAliasesTypeId anyAmbiguousType) {
+  int addAnyAmbiguousType(AnyAmbiguousAliasesTypeId? anyAmbiguousType) {
     fbBuilder.addUint8(45, anyAmbiguousType?.value);
     return fbBuilder.offset;
   }
-  int addAnyAmbiguousOffset(int offset) {
+  int addAnyAmbiguousOffset(int? offset) {
     fbBuilder.addOffset(46, offset);
     return fbBuilder.offset;
   }
-  int addVectorOfEnumsOffset(int offset) {
+  int addVectorOfEnumsOffset(int? offset) {
     fbBuilder.addOffset(47, offset);
     return fbBuilder.offset;
   }
-  int addSignedEnum(Race signedEnum) {
+  int addSignedEnum(Race? signedEnum) {
     fbBuilder.addInt8(48, signedEnum?.value);
     return fbBuilder.offset;
   }
-  int addTestrequirednestedflatbufferOffset(int offset) {
+  int addTestrequirednestedflatbufferOffset(int? offset) {
     fbBuilder.addOffset(49, offset);
     return fbBuilder.offset;
   }
-  int addScalarKeySortedTablesOffset(int offset) {
+  int addScalarKeySortedTablesOffset(int? offset) {
     fbBuilder.addOffset(50, offset);
     return fbBuilder.offset;
   }
@@ -1714,108 +1637,108 @@ class MonsterBuilder {
 }
 
 class MonsterObjectBuilder extends fb.ObjectBuilder {
-  final Vec3ObjectBuilder _pos;
-  final int _mana;
-  final int _hp;
-  final String _name;
-  final List<int> _inventory;
-  final Color _color;
-  final AnyTypeId _testType;
-  final dynamic _test;
-  final List<TestObjectBuilder> _test4;
-  final List<String> _testarrayofstring;
-  final List<MonsterObjectBuilder> _testarrayoftables;
-  final MonsterObjectBuilder _enemy;
-  final List<int> _testnestedflatbuffer;
-  final StatObjectBuilder _testempty;
-  final bool _testbool;
-  final int _testhashs32Fnv1;
-  final int _testhashu32Fnv1;
-  final int _testhashs64Fnv1;
-  final int _testhashu64Fnv1;
-  final int _testhashs32Fnv1a;
-  final int _testhashu32Fnv1a;
-  final int _testhashs64Fnv1a;
-  final int _testhashu64Fnv1a;
-  final List<bool> _testarrayofbools;
-  final double _testf;
-  final double _testf2;
-  final double _testf3;
-  final List<String> _testarrayofstring2;
-  final List<AbilityObjectBuilder> _testarrayofsortedstruct;
-  final List<int> _flex;
-  final List<TestObjectBuilder> _test5;
-  final List<int> _vectorOfLongs;
-  final List<double> _vectorOfDoubles;
-  final my_game.InParentNamespaceObjectBuilder _parentNamespaceTest;
-  final List<ReferrableObjectBuilder> _vectorOfReferrables;
-  final int _singleWeakReference;
-  final List<int> _vectorOfWeakReferences;
-  final List<ReferrableObjectBuilder> _vectorOfStrongReferrables;
-  final int _coOwningReference;
-  final List<int> _vectorOfCoOwningReferences;
-  final int _nonOwningReference;
-  final List<int> _vectorOfNonOwningReferences;
-  final AnyUniqueAliasesTypeId _anyUniqueType;
-  final dynamic _anyUnique;
-  final AnyAmbiguousAliasesTypeId _anyAmbiguousType;
-  final dynamic _anyAmbiguous;
-  final List<Color> _vectorOfEnums;
-  final Race _signedEnum;
-  final List<int> _testrequirednestedflatbuffer;
-  final List<StatObjectBuilder> _scalarKeySortedTables;
+  final Vec3ObjectBuilder? _pos;
+  final int? _mana;
+  final int? _hp;
+  final String? _name;
+  final List<int>? _inventory;
+  final Color? _color;
+  final AnyTypeId? _testType;
+  final dynamic? _test;
+  final List<TestObjectBuilder>? _test4;
+  final List<String>? _testarrayofstring;
+  final List<MonsterObjectBuilder>? _testarrayoftables;
+  final MonsterObjectBuilder? _enemy;
+  final List<int>? _testnestedflatbuffer;
+  final StatObjectBuilder? _testempty;
+  final bool? _testbool;
+  final int? _testhashs32Fnv1;
+  final int? _testhashu32Fnv1;
+  final int? _testhashs64Fnv1;
+  final int? _testhashu64Fnv1;
+  final int? _testhashs32Fnv1a;
+  final int? _testhashu32Fnv1a;
+  final int? _testhashs64Fnv1a;
+  final int? _testhashu64Fnv1a;
+  final List<bool>? _testarrayofbools;
+  final double? _testf;
+  final double? _testf2;
+  final double? _testf3;
+  final List<String>? _testarrayofstring2;
+  final List<AbilityObjectBuilder>? _testarrayofsortedstruct;
+  final List<int>? _flex;
+  final List<TestObjectBuilder>? _test5;
+  final List<int>? _vectorOfLongs;
+  final List<double>? _vectorOfDoubles;
+  final my_game.InParentNamespaceObjectBuilder? _parentNamespaceTest;
+  final List<ReferrableObjectBuilder>? _vectorOfReferrables;
+  final int? _singleWeakReference;
+  final List<int>? _vectorOfWeakReferences;
+  final List<ReferrableObjectBuilder>? _vectorOfStrongReferrables;
+  final int? _coOwningReference;
+  final List<int>? _vectorOfCoOwningReferences;
+  final int? _nonOwningReference;
+  final List<int>? _vectorOfNonOwningReferences;
+  final AnyUniqueAliasesTypeId? _anyUniqueType;
+  final dynamic? _anyUnique;
+  final AnyAmbiguousAliasesTypeId? _anyAmbiguousType;
+  final dynamic? _anyAmbiguous;
+  final List<Color>? _vectorOfEnums;
+  final Race? _signedEnum;
+  final List<int>? _testrequirednestedflatbuffer;
+  final List<StatObjectBuilder>? _scalarKeySortedTables;
 
   MonsterObjectBuilder({
-    Vec3ObjectBuilder pos,
-    int mana,
-    int hp,
-    String name,
-    List<int> inventory,
-    Color color,
-    AnyTypeId testType,
-    dynamic test,
-    List<TestObjectBuilder> test4,
-    List<String> testarrayofstring,
-    List<MonsterObjectBuilder> testarrayoftables,
-    MonsterObjectBuilder enemy,
-    List<int> testnestedflatbuffer,
-    StatObjectBuilder testempty,
-    bool testbool,
-    int testhashs32Fnv1,
-    int testhashu32Fnv1,
-    int testhashs64Fnv1,
-    int testhashu64Fnv1,
-    int testhashs32Fnv1a,
-    int testhashu32Fnv1a,
-    int testhashs64Fnv1a,
-    int testhashu64Fnv1a,
-    List<bool> testarrayofbools,
-    double testf,
-    double testf2,
-    double testf3,
-    List<String> testarrayofstring2,
-    List<AbilityObjectBuilder> testarrayofsortedstruct,
-    List<int> flex,
-    List<TestObjectBuilder> test5,
-    List<int> vectorOfLongs,
-    List<double> vectorOfDoubles,
-    my_game.InParentNamespaceObjectBuilder parentNamespaceTest,
-    List<ReferrableObjectBuilder> vectorOfReferrables,
-    int singleWeakReference,
-    List<int> vectorOfWeakReferences,
-    List<ReferrableObjectBuilder> vectorOfStrongReferrables,
-    int coOwningReference,
-    List<int> vectorOfCoOwningReferences,
-    int nonOwningReference,
-    List<int> vectorOfNonOwningReferences,
-    AnyUniqueAliasesTypeId anyUniqueType,
-    dynamic anyUnique,
-    AnyAmbiguousAliasesTypeId anyAmbiguousType,
-    dynamic anyAmbiguous,
-    List<Color> vectorOfEnums,
-    Race signedEnum,
-    List<int> testrequirednestedflatbuffer,
-    List<StatObjectBuilder> scalarKeySortedTables,
+    Vec3ObjectBuilder? pos,
+    int? mana,
+    int? hp,
+    String? name,
+    List<int>? inventory,
+    Color? color,
+    AnyTypeId? testType,
+    dynamic? test,
+    List<TestObjectBuilder>? test4,
+    List<String>? testarrayofstring,
+    List<MonsterObjectBuilder>? testarrayoftables,
+    MonsterObjectBuilder? enemy,
+    List<int>? testnestedflatbuffer,
+    StatObjectBuilder? testempty,
+    bool? testbool,
+    int? testhashs32Fnv1,
+    int? testhashu32Fnv1,
+    int? testhashs64Fnv1,
+    int? testhashu64Fnv1,
+    int? testhashs32Fnv1a,
+    int? testhashu32Fnv1a,
+    int? testhashs64Fnv1a,
+    int? testhashu64Fnv1a,
+    List<bool>? testarrayofbools,
+    double? testf,
+    double? testf2,
+    double? testf3,
+    List<String>? testarrayofstring2,
+    List<AbilityObjectBuilder>? testarrayofsortedstruct,
+    List<int>? flex,
+    List<TestObjectBuilder>? test5,
+    List<int>? vectorOfLongs,
+    List<double>? vectorOfDoubles,
+    my_game.InParentNamespaceObjectBuilder? parentNamespaceTest,
+    List<ReferrableObjectBuilder>? vectorOfReferrables,
+    int? singleWeakReference,
+    List<int>? vectorOfWeakReferences,
+    List<ReferrableObjectBuilder>? vectorOfStrongReferrables,
+    int? coOwningReference,
+    List<int>? vectorOfCoOwningReferences,
+    int? nonOwningReference,
+    List<int>? vectorOfNonOwningReferences,
+    AnyUniqueAliasesTypeId? anyUniqueType,
+    dynamic? anyUnique,
+    AnyAmbiguousAliasesTypeId? anyAmbiguousType,
+    dynamic? anyAmbiguous,
+    List<Color>? vectorOfEnums,
+    Race? signedEnum,
+    List<int>? testrequirednestedflatbuffer,
+    List<StatObjectBuilder>? scalarKeySortedTables,
   })
       : _pos = pos,
         _mana = mana,
@@ -1870,112 +1793,91 @@ class MonsterObjectBuilder extends fb.ObjectBuilder {
 
   /// Finish building, and store into the [fbBuilder].
   @override
-  int finish(
-    fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-    final int nameOffset = fbBuilder.writeString(_name);
-    final int inventoryOffset = _inventory?.isNotEmpty == true
-        ? fbBuilder.writeListUint8(_inventory)
+  int finish(fb.Builder fbBuilder) {
+    final int? nameOffset = fbBuilder.writeString(_name);
+    final int? inventoryOffset = _inventory?.isNotEmpty == true
+        ? fbBuilder.writeListUint8(_inventory!)
         : null;
-    final int testOffset = _test?.getOrCreateOffset(fbBuilder);
-    final int test4Offset = _test4?.isNotEmpty == true
-        ? fbBuilder.writeListOfStructs(_test4)
+    final int? testOffset = _test?.getOrCreateOffset(fbBuilder);
+    final int? test4Offset = _test4?.isNotEmpty == true
+        ? fbBuilder.writeListOfStructs(_test4!)
         : null;
-    final int testarrayofstringOffset = _testarrayofstring?.isNotEmpty == true
-        ? fbBuilder.writeList(_testarrayofstring.map((b) => fbBuilder.writeString(b)).toList())
+    final int? testarrayofstringOffset = _testarrayofstring?.isNotEmpty == true
+        ? fbBuilder.writeList(_testarrayofstring!.map((b) => fbBuilder.writeString(b)!).toList())
         : null;
-    final int testarrayoftablesOffset = _testarrayoftables?.isNotEmpty == true
-        ? fbBuilder.writeList(_testarrayoftables.map((b) => b.getOrCreateOffset(fbBuilder)).toList())
+    final int? testarrayoftablesOffset = _testarrayoftables?.isNotEmpty == true
+        ? fbBuilder.writeList(_testarrayoftables!.map((b) => b.getOrCreateOffset(fbBuilder)).toList())
         : null;
-    final int enemyOffset = _enemy?.getOrCreateOffset(fbBuilder);
-    final int testnestedflatbufferOffset = _testnestedflatbuffer?.isNotEmpty == true
-        ? fbBuilder.writeListUint8(_testnestedflatbuffer)
+    final int? enemyOffset = _enemy?.getOrCreateOffset(fbBuilder);
+    final int? testnestedflatbufferOffset = _testnestedflatbuffer?.isNotEmpty == true
+        ? fbBuilder.writeListUint8(_testnestedflatbuffer!)
         : null;
-    final int testemptyOffset = _testempty?.getOrCreateOffset(fbBuilder);
-    final int testarrayofboolsOffset = _testarrayofbools?.isNotEmpty == true
-        ? fbBuilder.writeListBool(_testarrayofbools)
+    final int? testemptyOffset = _testempty?.getOrCreateOffset(fbBuilder);
+    final int? testarrayofboolsOffset = _testarrayofbools?.isNotEmpty == true
+        ? fbBuilder.writeListBool(_testarrayofbools!)
         : null;
-    final int testarrayofstring2Offset = _testarrayofstring2?.isNotEmpty == true
-        ? fbBuilder.writeList(_testarrayofstring2.map((b) => fbBuilder.writeString(b)).toList())
+    final int? testarrayofstring2Offset = _testarrayofstring2?.isNotEmpty == true
+        ? fbBuilder.writeList(_testarrayofstring2!.map((b) => fbBuilder.writeString(b)!).toList())
         : null;
-    final int testarrayofsortedstructOffset = _testarrayofsortedstruct?.isNotEmpty == true
-        ? fbBuilder.writeListOfStructs(_testarrayofsortedstruct)
+    final int? testarrayofsortedstructOffset = _testarrayofsortedstruct?.isNotEmpty == true
+        ? fbBuilder.writeListOfStructs(_testarrayofsortedstruct!)
         : null;
-    final int flexOffset = _flex?.isNotEmpty == true
-        ? fbBuilder.writeListUint8(_flex)
+    final int? flexOffset = _flex?.isNotEmpty == true
+        ? fbBuilder.writeListUint8(_flex!)
         : null;
-    final int test5Offset = _test5?.isNotEmpty == true
-        ? fbBuilder.writeListOfStructs(_test5)
+    final int? test5Offset = _test5?.isNotEmpty == true
+        ? fbBuilder.writeListOfStructs(_test5!)
         : null;
-    final int vectorOfLongsOffset = _vectorOfLongs?.isNotEmpty == true
-        ? fbBuilder.writeListInt64(_vectorOfLongs)
+    final int? vectorOfLongsOffset = _vectorOfLongs?.isNotEmpty == true
+        ? fbBuilder.writeListInt64(_vectorOfLongs!)
         : null;
-    final int vectorOfDoublesOffset = _vectorOfDoubles?.isNotEmpty == true
-        ? fbBuilder.writeListFloat64(_vectorOfDoubles)
+    final int? vectorOfDoublesOffset = _vectorOfDoubles?.isNotEmpty == true
+        ? fbBuilder.writeListFloat64(_vectorOfDoubles!)
         : null;
-    final int parentNamespaceTestOffset = _parentNamespaceTest?.getOrCreateOffset(fbBuilder);
-    final int vectorOfReferrablesOffset = _vectorOfReferrables?.isNotEmpty == true
-        ? fbBuilder.writeList(_vectorOfReferrables.map((b) => b.getOrCreateOffset(fbBuilder)).toList())
+    final int? parentNamespaceTestOffset = _parentNamespaceTest?.getOrCreateOffset(fbBuilder);
+    final int? vectorOfReferrablesOffset = _vectorOfReferrables?.isNotEmpty == true
+        ? fbBuilder.writeList(_vectorOfReferrables!.map((b) => b.getOrCreateOffset(fbBuilder)).toList())
         : null;
-    final int vectorOfWeakReferencesOffset = _vectorOfWeakReferences?.isNotEmpty == true
-        ? fbBuilder.writeListUint64(_vectorOfWeakReferences)
+    final int? vectorOfWeakReferencesOffset = _vectorOfWeakReferences?.isNotEmpty == true
+        ? fbBuilder.writeListUint64(_vectorOfWeakReferences!)
         : null;
-    final int vectorOfStrongReferrablesOffset = _vectorOfStrongReferrables?.isNotEmpty == true
-        ? fbBuilder.writeList(_vectorOfStrongReferrables.map((b) => b.getOrCreateOffset(fbBuilder)).toList())
+    final int? vectorOfStrongReferrablesOffset = _vectorOfStrongReferrables?.isNotEmpty == true
+        ? fbBuilder.writeList(_vectorOfStrongReferrables!.map((b) => b.getOrCreateOffset(fbBuilder)).toList())
         : null;
-    final int vectorOfCoOwningReferencesOffset = _vectorOfCoOwningReferences?.isNotEmpty == true
-        ? fbBuilder.writeListUint64(_vectorOfCoOwningReferences)
+    final int? vectorOfCoOwningReferencesOffset = _vectorOfCoOwningReferences?.isNotEmpty == true
+        ? fbBuilder.writeListUint64(_vectorOfCoOwningReferences!)
         : null;
-    final int vectorOfNonOwningReferencesOffset = _vectorOfNonOwningReferences?.isNotEmpty == true
-        ? fbBuilder.writeListUint64(_vectorOfNonOwningReferences)
+    final int? vectorOfNonOwningReferencesOffset = _vectorOfNonOwningReferences?.isNotEmpty == true
+        ? fbBuilder.writeListUint64(_vectorOfNonOwningReferences!)
         : null;
-    final int anyUniqueOffset = _anyUnique?.getOrCreateOffset(fbBuilder);
-    final int anyAmbiguousOffset = _anyAmbiguous?.getOrCreateOffset(fbBuilder);
-    final int vectorOfEnumsOffset = _vectorOfEnums?.isNotEmpty == true
-        ? fbBuilder.writeListUint8(_vectorOfEnums.map((f) => f.value).toList())
+    final int? anyUniqueOffset = _anyUnique?.getOrCreateOffset(fbBuilder);
+    final int? anyAmbiguousOffset = _anyAmbiguous?.getOrCreateOffset(fbBuilder);
+    final int? vectorOfEnumsOffset = _vectorOfEnums?.isNotEmpty == true
+        ? fbBuilder.writeListUint8(_vectorOfEnums!.map((f) => f.value).toList())
         : null;
-    final int testrequirednestedflatbufferOffset = _testrequirednestedflatbuffer?.isNotEmpty == true
-        ? fbBuilder.writeListUint8(_testrequirednestedflatbuffer)
+    final int? testrequirednestedflatbufferOffset = _testrequirednestedflatbuffer?.isNotEmpty == true
+        ? fbBuilder.writeListUint8(_testrequirednestedflatbuffer!)
         : null;
-    final int scalarKeySortedTablesOffset = _scalarKeySortedTables?.isNotEmpty == true
-        ? fbBuilder.writeList(_scalarKeySortedTables.map((b) => b.getOrCreateOffset(fbBuilder)).toList())
+    final int? scalarKeySortedTablesOffset = _scalarKeySortedTables?.isNotEmpty == true
+        ? fbBuilder.writeList(_scalarKeySortedTables!.map((b) => b.getOrCreateOffset(fbBuilder)).toList())
         : null;
-
     fbBuilder.startTable();
     if (_pos != null) {
-      fbBuilder.addStruct(0, _pos.finish(fbBuilder));
+      fbBuilder.addStruct(0, _pos!.finish(fbBuilder));
     }
     fbBuilder.addInt16(1, _mana);
     fbBuilder.addInt16(2, _hp);
-    if (nameOffset != null) {
-      fbBuilder.addOffset(3, nameOffset);
-    }
-    if (inventoryOffset != null) {
-      fbBuilder.addOffset(5, inventoryOffset);
-    }
+    fbBuilder.addOffset(3, nameOffset);
+    fbBuilder.addOffset(5, inventoryOffset);
     fbBuilder.addUint8(6, _color?.value);
     fbBuilder.addUint8(7, _testType?.value);
-    if (testOffset != null) {
-      fbBuilder.addOffset(8, testOffset);
-    }
-    if (test4Offset != null) {
-      fbBuilder.addOffset(9, test4Offset);
-    }
-    if (testarrayofstringOffset != null) {
-      fbBuilder.addOffset(10, testarrayofstringOffset);
-    }
-    if (testarrayoftablesOffset != null) {
-      fbBuilder.addOffset(11, testarrayoftablesOffset);
-    }
-    if (enemyOffset != null) {
-      fbBuilder.addOffset(12, enemyOffset);
-    }
-    if (testnestedflatbufferOffset != null) {
-      fbBuilder.addOffset(13, testnestedflatbufferOffset);
-    }
-    if (testemptyOffset != null) {
-      fbBuilder.addOffset(14, testemptyOffset);
-    }
+    fbBuilder.addOffset(8, testOffset);
+    fbBuilder.addOffset(9, test4Offset);
+    fbBuilder.addOffset(10, testarrayofstringOffset);
+    fbBuilder.addOffset(11, testarrayoftablesOffset);
+    fbBuilder.addOffset(12, enemyOffset);
+    fbBuilder.addOffset(13, testnestedflatbufferOffset);
+    fbBuilder.addOffset(14, testemptyOffset);
     fbBuilder.addBool(15, _testbool);
     fbBuilder.addInt32(16, _testhashs32Fnv1);
     fbBuilder.addUint32(17, _testhashu32Fnv1);
@@ -1985,75 +1887,39 @@ class MonsterObjectBuilder extends fb.ObjectBuilder {
     fbBuilder.addUint32(21, _testhashu32Fnv1a);
     fbBuilder.addInt64(22, _testhashs64Fnv1a);
     fbBuilder.addUint64(23, _testhashu64Fnv1a);
-    if (testarrayofboolsOffset != null) {
-      fbBuilder.addOffset(24, testarrayofboolsOffset);
-    }
+    fbBuilder.addOffset(24, testarrayofboolsOffset);
     fbBuilder.addFloat32(25, _testf);
     fbBuilder.addFloat32(26, _testf2);
     fbBuilder.addFloat32(27, _testf3);
-    if (testarrayofstring2Offset != null) {
-      fbBuilder.addOffset(28, testarrayofstring2Offset);
-    }
-    if (testarrayofsortedstructOffset != null) {
-      fbBuilder.addOffset(29, testarrayofsortedstructOffset);
-    }
-    if (flexOffset != null) {
-      fbBuilder.addOffset(30, flexOffset);
-    }
-    if (test5Offset != null) {
-      fbBuilder.addOffset(31, test5Offset);
-    }
-    if (vectorOfLongsOffset != null) {
-      fbBuilder.addOffset(32, vectorOfLongsOffset);
-    }
-    if (vectorOfDoublesOffset != null) {
-      fbBuilder.addOffset(33, vectorOfDoublesOffset);
-    }
-    if (parentNamespaceTestOffset != null) {
-      fbBuilder.addOffset(34, parentNamespaceTestOffset);
-    }
-    if (vectorOfReferrablesOffset != null) {
-      fbBuilder.addOffset(35, vectorOfReferrablesOffset);
-    }
+    fbBuilder.addOffset(28, testarrayofstring2Offset);
+    fbBuilder.addOffset(29, testarrayofsortedstructOffset);
+    fbBuilder.addOffset(30, flexOffset);
+    fbBuilder.addOffset(31, test5Offset);
+    fbBuilder.addOffset(32, vectorOfLongsOffset);
+    fbBuilder.addOffset(33, vectorOfDoublesOffset);
+    fbBuilder.addOffset(34, parentNamespaceTestOffset);
+    fbBuilder.addOffset(35, vectorOfReferrablesOffset);
     fbBuilder.addUint64(36, _singleWeakReference);
-    if (vectorOfWeakReferencesOffset != null) {
-      fbBuilder.addOffset(37, vectorOfWeakReferencesOffset);
-    }
-    if (vectorOfStrongReferrablesOffset != null) {
-      fbBuilder.addOffset(38, vectorOfStrongReferrablesOffset);
-    }
+    fbBuilder.addOffset(37, vectorOfWeakReferencesOffset);
+    fbBuilder.addOffset(38, vectorOfStrongReferrablesOffset);
     fbBuilder.addUint64(39, _coOwningReference);
-    if (vectorOfCoOwningReferencesOffset != null) {
-      fbBuilder.addOffset(40, vectorOfCoOwningReferencesOffset);
-    }
+    fbBuilder.addOffset(40, vectorOfCoOwningReferencesOffset);
     fbBuilder.addUint64(41, _nonOwningReference);
-    if (vectorOfNonOwningReferencesOffset != null) {
-      fbBuilder.addOffset(42, vectorOfNonOwningReferencesOffset);
-    }
+    fbBuilder.addOffset(42, vectorOfNonOwningReferencesOffset);
     fbBuilder.addUint8(43, _anyUniqueType?.value);
-    if (anyUniqueOffset != null) {
-      fbBuilder.addOffset(44, anyUniqueOffset);
-    }
+    fbBuilder.addOffset(44, anyUniqueOffset);
     fbBuilder.addUint8(45, _anyAmbiguousType?.value);
-    if (anyAmbiguousOffset != null) {
-      fbBuilder.addOffset(46, anyAmbiguousOffset);
-    }
-    if (vectorOfEnumsOffset != null) {
-      fbBuilder.addOffset(47, vectorOfEnumsOffset);
-    }
+    fbBuilder.addOffset(46, anyAmbiguousOffset);
+    fbBuilder.addOffset(47, vectorOfEnumsOffset);
     fbBuilder.addInt8(48, _signedEnum?.value);
-    if (testrequirednestedflatbufferOffset != null) {
-      fbBuilder.addOffset(49, testrequirednestedflatbufferOffset);
-    }
-    if (scalarKeySortedTablesOffset != null) {
-      fbBuilder.addOffset(50, scalarKeySortedTablesOffset);
-    }
+    fbBuilder.addOffset(49, testrequirednestedflatbufferOffset);
+    fbBuilder.addOffset(50, scalarKeySortedTablesOffset);
     return fbBuilder.endTable();
   }
 
   /// Convenience method to serialize to byte list.
   @override
-  Uint8List toBytes([String fileIdentifier]) {
+  Uint8List toBytes([String? fileIdentifier]) {
     fb.Builder fbBuilder = new fb.Builder();
     int offset = finish(fbBuilder);
     return fbBuilder.finish(offset, fileIdentifier);
@@ -2081,8 +1947,8 @@ class TypeAliases {
   int get u64 => const fb.Uint64Reader().vTableGet(_bc, _bcOffset, 18, 0);
   double get f32 => const fb.Float32Reader().vTableGet(_bc, _bcOffset, 20, 0.0);
   double get f64 => const fb.Float64Reader().vTableGet(_bc, _bcOffset, 22, 0.0);
-  List<int> get v8 => const fb.ListReader<int>(const fb.Int8Reader()).vTableGet(_bc, _bcOffset, 24, null);
-  List<double> get vf64 => const fb.ListReader<double>(const fb.Float64Reader()).vTableGet(_bc, _bcOffset, 26, null);
+  List<int>? get v8 => const fb.ListReader<int>(const fb.Int8Reader()).vTableGetNullable(_bc, _bcOffset, 24);
+  List<double>? get vf64 => const fb.ListReader<double>(const fb.Float64Reader()).vTableGetNullable(_bc, _bcOffset, 26);
 
   @override
   String toString() {
@@ -2103,7 +1969,7 @@ class TypeAliases {
       v8: v8,
       vf64: vf64);
 
-  static int pack(fb.Builder fbBuilder, TypeAliasesT object) {
+  static int pack(fb.Builder fbBuilder, TypeAliasesT? object) {
     if (object == null) return 0;
     return object.pack(fbBuilder);
   }
@@ -2120,32 +1986,30 @@ class TypeAliasesT {
   int u64;
   double f32;
   double f64;
-  List<int> v8;
-  List<double> vf64;
+  List<int>? v8;
+  List<double>? vf64;
 
   TypeAliasesT({
-      this.i8,
-      this.u8,
-      this.i16,
-      this.u16,
-      this.i32,
-      this.u32,
-      this.i64,
-      this.u64,
-      this.f32,
-      this.f64,
+      this.i8 = 0,
+      this.u8 = 0,
+      this.i16 = 0,
+      this.u16 = 0,
+      this.i32 = 0,
+      this.u32 = 0,
+      this.i64 = 0,
+      this.u64 = 0,
+      this.f32 = 0.0,
+      this.f64 = 0.0,
       this.v8,
       this.vf64});
 
   int pack(fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-    final int v8Offset = v8?.isNotEmpty == true
-        ? fbBuilder.writeListInt8(v8)
+    final int? v8Offset = v8?.isNotEmpty == true
+        ? fbBuilder.writeListInt8(v8!)
         : null;
-    final int vf64Offset = vf64?.isNotEmpty == true
-        ? fbBuilder.writeListFloat64(vf64)
+    final int? vf64Offset = vf64?.isNotEmpty == true
+        ? fbBuilder.writeListFloat64(vf64!)
         : null;
-
     fbBuilder.startTable();
     fbBuilder.addInt8(0, i8);
     fbBuilder.addUint8(1, u8);
@@ -2157,12 +2021,8 @@ class TypeAliasesT {
     fbBuilder.addUint64(7, u64);
     fbBuilder.addFloat32(8, f32);
     fbBuilder.addFloat64(9, f64);
-    if (v8Offset != null) {
-      fbBuilder.addOffset(10, v8Offset);
-    }
-    if (vf64Offset != null) {
-      fbBuilder.addOffset(11, vf64Offset);
-    }
+    fbBuilder.addOffset(10, v8Offset);
+    fbBuilder.addOffset(11, vf64Offset);
     return fbBuilder.endTable();
   }
 
@@ -2181,9 +2041,7 @@ class _TypeAliasesReader extends fb.TableReader<TypeAliases> {
 }
 
 class TypeAliasesBuilder {
-  TypeAliasesBuilder(this.fbBuilder) {
-    assert(fbBuilder != null);
-  }
+  TypeAliasesBuilder(this.fbBuilder) {}
 
   final fb.Builder fbBuilder;
 
@@ -2191,51 +2049,51 @@ class TypeAliasesBuilder {
     fbBuilder.startTable();
   }
 
-  int addI8(int i8) {
+  int addI8(int? i8) {
     fbBuilder.addInt8(0, i8);
     return fbBuilder.offset;
   }
-  int addU8(int u8) {
+  int addU8(int? u8) {
     fbBuilder.addUint8(1, u8);
     return fbBuilder.offset;
   }
-  int addI16(int i16) {
+  int addI16(int? i16) {
     fbBuilder.addInt16(2, i16);
     return fbBuilder.offset;
   }
-  int addU16(int u16) {
+  int addU16(int? u16) {
     fbBuilder.addUint16(3, u16);
     return fbBuilder.offset;
   }
-  int addI32(int i32) {
+  int addI32(int? i32) {
     fbBuilder.addInt32(4, i32);
     return fbBuilder.offset;
   }
-  int addU32(int u32) {
+  int addU32(int? u32) {
     fbBuilder.addUint32(5, u32);
     return fbBuilder.offset;
   }
-  int addI64(int i64) {
+  int addI64(int? i64) {
     fbBuilder.addInt64(6, i64);
     return fbBuilder.offset;
   }
-  int addU64(int u64) {
+  int addU64(int? u64) {
     fbBuilder.addUint64(7, u64);
     return fbBuilder.offset;
   }
-  int addF32(double f32) {
+  int addF32(double? f32) {
     fbBuilder.addFloat32(8, f32);
     return fbBuilder.offset;
   }
-  int addF64(double f64) {
+  int addF64(double? f64) {
     fbBuilder.addFloat64(9, f64);
     return fbBuilder.offset;
   }
-  int addV8Offset(int offset) {
+  int addV8Offset(int? offset) {
     fbBuilder.addOffset(10, offset);
     return fbBuilder.offset;
   }
-  int addVf64Offset(int offset) {
+  int addVf64Offset(int? offset) {
     fbBuilder.addOffset(11, offset);
     return fbBuilder.offset;
   }
@@ -2246,32 +2104,32 @@ class TypeAliasesBuilder {
 }
 
 class TypeAliasesObjectBuilder extends fb.ObjectBuilder {
-  final int _i8;
-  final int _u8;
-  final int _i16;
-  final int _u16;
-  final int _i32;
-  final int _u32;
-  final int _i64;
-  final int _u64;
-  final double _f32;
-  final double _f64;
-  final List<int> _v8;
-  final List<double> _vf64;
+  final int? _i8;
+  final int? _u8;
+  final int? _i16;
+  final int? _u16;
+  final int? _i32;
+  final int? _u32;
+  final int? _i64;
+  final int? _u64;
+  final double? _f32;
+  final double? _f64;
+  final List<int>? _v8;
+  final List<double>? _vf64;
 
   TypeAliasesObjectBuilder({
-    int i8,
-    int u8,
-    int i16,
-    int u16,
-    int i32,
-    int u32,
-    int i64,
-    int u64,
-    double f32,
-    double f64,
-    List<int> v8,
-    List<double> vf64,
+    int? i8,
+    int? u8,
+    int? i16,
+    int? u16,
+    int? i32,
+    int? u32,
+    int? i64,
+    int? u64,
+    double? f32,
+    double? f64,
+    List<int>? v8,
+    List<double>? vf64,
   })
       : _i8 = i8,
         _u8 = u8,
@@ -2288,16 +2146,13 @@ class TypeAliasesObjectBuilder extends fb.ObjectBuilder {
 
   /// Finish building, and store into the [fbBuilder].
   @override
-  int finish(
-    fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-    final int v8Offset = _v8?.isNotEmpty == true
-        ? fbBuilder.writeListInt8(_v8)
+  int finish(fb.Builder fbBuilder) {
+    final int? v8Offset = _v8?.isNotEmpty == true
+        ? fbBuilder.writeListInt8(_v8!)
         : null;
-    final int vf64Offset = _vf64?.isNotEmpty == true
-        ? fbBuilder.writeListFloat64(_vf64)
+    final int? vf64Offset = _vf64?.isNotEmpty == true
+        ? fbBuilder.writeListFloat64(_vf64!)
         : null;
-
     fbBuilder.startTable();
     fbBuilder.addInt8(0, _i8);
     fbBuilder.addUint8(1, _u8);
@@ -2309,18 +2164,14 @@ class TypeAliasesObjectBuilder extends fb.ObjectBuilder {
     fbBuilder.addUint64(7, _u64);
     fbBuilder.addFloat32(8, _f32);
     fbBuilder.addFloat64(9, _f64);
-    if (v8Offset != null) {
-      fbBuilder.addOffset(10, v8Offset);
-    }
-    if (vf64Offset != null) {
-      fbBuilder.addOffset(11, vf64Offset);
-    }
+    fbBuilder.addOffset(10, v8Offset);
+    fbBuilder.addOffset(11, vf64Offset);
     return fbBuilder.endTable();
   }
 
   /// Convenience method to serialize to byte list.
   @override
-  Uint8List toBytes([String fileIdentifier]) {
+  Uint8List toBytes([String? fileIdentifier]) {
     fb.Builder fbBuilder = new fb.Builder();
     int offset = finish(fbBuilder);
     return fbBuilder.finish(offset, fileIdentifier);
diff --git a/tests/monster_test_my_game_generated.dart b/tests/monster_test_my_game_generated.dart
index d53550d131e..146c401788a 100644
--- a/tests/monster_test_my_game_generated.dart
+++ b/tests/monster_test_my_game_generated.dart
@@ -1,5 +1,5 @@
 // automatically generated by the FlatBuffers compiler, do not modify
-// ignore_for_file: unused_import, unused_field, unused_local_variable
+// ignore_for_file: unused_import, unused_field, unused_element, unused_local_variable
 
 library my_game;
 
@@ -29,7 +29,7 @@ class InParentNamespace {
 
   InParentNamespaceT unpack() => InParentNamespaceT();
 
-  static int pack(fb.Builder fbBuilder, InParentNamespaceT object) {
+  static int pack(fb.Builder fbBuilder, InParentNamespaceT? object) {
     if (object == null) return 0;
     return object.pack(fbBuilder);
   }
@@ -37,8 +37,6 @@ class InParentNamespace {
 
 class InParentNamespaceT {
   int pack(fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-
     fbBuilder.startTable();
     return fbBuilder.endTable();
   }
@@ -63,17 +61,14 @@ class InParentNamespaceObjectBuilder extends fb.ObjectBuilder {
 
   /// Finish building, and store into the [fbBuilder].
   @override
-  int finish(
-    fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-
+  int finish(fb.Builder fbBuilder) {
     fbBuilder.startTable();
     return fbBuilder.endTable();
   }
 
   /// Convenience method to serialize to byte list.
   @override
-  Uint8List toBytes([String fileIdentifier]) {
+  Uint8List toBytes([String? fileIdentifier]) {
     fb.Builder fbBuilder = new fb.Builder();
     int offset = finish(fbBuilder);
     return fbBuilder.finish(offset, fileIdentifier);
diff --git a/tests/namespace_test/namespace_test1_namespace_a.namespace_b_generated.dart b/tests/namespace_test/namespace_test1_namespace_a.namespace_b_generated.dart
index c36d1e00026..7f9cc3bb119 100644
--- a/tests/namespace_test/namespace_test1_namespace_a.namespace_b_generated.dart
+++ b/tests/namespace_test/namespace_test1_namespace_a.namespace_b_generated.dart
@@ -1,5 +1,5 @@
 // automatically generated by the FlatBuffers compiler, do not modify
-// ignore_for_file: unused_import, unused_field, unused_local_variable
+// ignore_for_file: unused_import, unused_field, unused_element, unused_local_variable
 
 library namespace_a.namespace_b;
 
@@ -12,20 +12,25 @@ class UnionInNestedNSTypeId {
   const UnionInNestedNSTypeId._(this.value);
 
   factory UnionInNestedNSTypeId.fromValue(int value) {
-    if (value == null) value = 0;
-    if (!values.containsKey(value)) {
+    final result = values[value];
+    if (result == null) {
       throw new StateError('Invalid value $value for bit flag enum UnionInNestedNSTypeId');
     }
-    return values[value];
+    return result;
   }
 
+  static UnionInNestedNSTypeId? _createOrNull(int? value) => 
+      value == null ? null : UnionInNestedNSTypeId.fromValue(value);
+
   static const int minValue = 0;
   static const int maxValue = 1;
   static bool containsValue(int value) => values.containsKey(value);
 
   static const UnionInNestedNSTypeId NONE = const UnionInNestedNSTypeId._(0);
   static const UnionInNestedNSTypeId TableInNestedNS = const UnionInNestedNSTypeId._(1);
-  static const Map<int,UnionInNestedNSTypeId> values = {0: NONE,1: TableInNestedNS,};
+  static const Map<int, UnionInNestedNSTypeId> values = {
+    0: NONE,
+    1: TableInNestedNS};
 
   static const fb.Reader<UnionInNestedNSTypeId> reader = const _UnionInNestedNSTypeIdReader();
 
@@ -51,13 +56,16 @@ class EnumInNestedNS {
   const EnumInNestedNS._(this.value);
 
   factory EnumInNestedNS.fromValue(int value) {
-    if (value == null) value = 0;
-    if (!values.containsKey(value)) {
+    final result = values[value];
+    if (result == null) {
       throw new StateError('Invalid value $value for bit flag enum EnumInNestedNS');
     }
-    return values[value];
+    return result;
   }
 
+  static EnumInNestedNS? _createOrNull(int? value) => 
+      value == null ? null : EnumInNestedNS.fromValue(value);
+
   static const int minValue = 0;
   static const int maxValue = 2;
   static bool containsValue(int value) => values.containsKey(value);
@@ -65,7 +73,10 @@ class EnumInNestedNS {
   static const EnumInNestedNS A = const EnumInNestedNS._(0);
   static const EnumInNestedNS B = const EnumInNestedNS._(1);
   static const EnumInNestedNS C = const EnumInNestedNS._(2);
-  static const Map<int,EnumInNestedNS> values = {0: A,1: B,2: C,};
+  static const Map<int, EnumInNestedNS> values = {
+    0: A,
+    1: B,
+    2: C};
 
   static const fb.Reader<EnumInNestedNS> reader = const _EnumInNestedNSReader();
 
@@ -108,7 +119,7 @@ class TableInNestedNS {
   TableInNestedNST unpack() => TableInNestedNST(
       foo: foo);
 
-  static int pack(fb.Builder fbBuilder, TableInNestedNST object) {
+  static int pack(fb.Builder fbBuilder, TableInNestedNST? object) {
     if (object == null) return 0;
     return object.pack(fbBuilder);
   }
@@ -118,11 +129,9 @@ class TableInNestedNST {
   int foo;
 
   TableInNestedNST({
-      this.foo});
+      this.foo = 0});
 
   int pack(fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-
     fbBuilder.startTable();
     fbBuilder.addInt32(0, foo);
     return fbBuilder.endTable();
@@ -143,9 +152,7 @@ class _TableInNestedNSReader extends fb.TableReader<TableInNestedNS> {
 }
 
 class TableInNestedNSBuilder {
-  TableInNestedNSBuilder(this.fbBuilder) {
-    assert(fbBuilder != null);
-  }
+  TableInNestedNSBuilder(this.fbBuilder) {}
 
   final fb.Builder fbBuilder;
 
@@ -153,7 +160,7 @@ class TableInNestedNSBuilder {
     fbBuilder.startTable();
   }
 
-  int addFoo(int foo) {
+  int addFoo(int? foo) {
     fbBuilder.addInt32(0, foo);
     return fbBuilder.offset;
   }
@@ -164,19 +171,16 @@ class TableInNestedNSBuilder {
 }
 
 class TableInNestedNSObjectBuilder extends fb.ObjectBuilder {
-  final int _foo;
+  final int? _foo;
 
   TableInNestedNSObjectBuilder({
-    int foo,
+    int? foo,
   })
       : _foo = foo;
 
   /// Finish building, and store into the [fbBuilder].
   @override
-  int finish(
-    fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-
+  int finish(fb.Builder fbBuilder) {
     fbBuilder.startTable();
     fbBuilder.addInt32(0, _foo);
     return fbBuilder.endTable();
@@ -184,7 +188,7 @@ class TableInNestedNSObjectBuilder extends fb.ObjectBuilder {
 
   /// Convenience method to serialize to byte list.
   @override
-  Uint8List toBytes([String fileIdentifier]) {
+  Uint8List toBytes([String? fileIdentifier]) {
     fb.Builder fbBuilder = new fb.Builder();
     int offset = finish(fbBuilder);
     return fbBuilder.finish(offset, fileIdentifier);
@@ -210,7 +214,7 @@ class StructInNestedNS {
       a: a,
       b: b);
 
-  static int pack(fb.Builder fbBuilder, StructInNestedNST object) {
+  static int pack(fb.Builder fbBuilder, StructInNestedNST? object) {
     if (object == null) return 0;
     return object.pack(fbBuilder);
   }
@@ -221,12 +225,10 @@ class StructInNestedNST {
   int b;
 
   StructInNestedNST({
-      this.a,
-      this.b});
+      required this.a,
+      required this.b});
 
   int pack(fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-
     fbBuilder.putInt32(b);
     fbBuilder.putInt32(a);
     return fbBuilder.offset;
@@ -250,9 +252,7 @@ class _StructInNestedNSReader extends fb.StructReader<StructInNestedNS> {
 }
 
 class StructInNestedNSBuilder {
-  StructInNestedNSBuilder(this.fbBuilder) {
-    assert(fbBuilder != null);
-  }
+  StructInNestedNSBuilder(this.fbBuilder) {}
 
   final fb.Builder fbBuilder;
 
@@ -269,18 +269,15 @@ class StructInNestedNSObjectBuilder extends fb.ObjectBuilder {
   final int _b;
 
   StructInNestedNSObjectBuilder({
-    int a,
-    int b,
+    required int a,
+    required int b,
   })
       : _a = a,
         _b = b;
 
   /// Finish building, and store into the [fbBuilder].
   @override
-  int finish(
-    fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-
+  int finish(fb.Builder fbBuilder) {
     fbBuilder.putInt32(_b);
     fbBuilder.putInt32(_a);
     return fbBuilder.offset;
@@ -288,7 +285,7 @@ class StructInNestedNSObjectBuilder extends fb.ObjectBuilder {
 
   /// Convenience method to serialize to byte list.
   @override
-  Uint8List toBytes([String fileIdentifier]) {
+  Uint8List toBytes([String? fileIdentifier]) {
     fb.Builder fbBuilder = new fb.Builder();
     int offset = finish(fbBuilder);
     return fbBuilder.finish(offset, fileIdentifier);
diff --git a/tests/namespace_test/namespace_test2_namespace_a_generated.dart b/tests/namespace_test/namespace_test2_namespace_a_generated.dart
index 79a82a2c7de..87c16195088 100644
--- a/tests/namespace_test/namespace_test2_namespace_a_generated.dart
+++ b/tests/namespace_test/namespace_test2_namespace_a_generated.dart
@@ -1,5 +1,5 @@
 // automatically generated by the FlatBuffers compiler, do not modify
-// ignore_for_file: unused_import, unused_field, unused_local_variable
+// ignore_for_file: unused_import, unused_field, unused_element, unused_local_variable
 
 library namespace_a;
 
@@ -20,16 +20,16 @@ class TableInFirstNS {
   final fb.BufferContext _bc;
   final int _bcOffset;
 
-  namespace_a_namespace_b.TableInNestedNS get fooTable => namespace_a_namespace_b.TableInNestedNS.reader.vTableGet(_bc, _bcOffset, 4, null);
-  EnumInNestedNS get fooEnum => new EnumInNestedNS.fromValue(const fb.Int8Reader().vTableGet(_bc, _bcOffset, 6, 0));
-  UnionInNestedNSTypeId get fooUnionType => new UnionInNestedNSTypeId.fromValue(const fb.Uint8Reader().vTableGet(_bc, _bcOffset, 8, 0));
-  dynamic get fooUnion {
+  namespace_a_namespace_b.TableInNestedNS? get fooTable => namespace_a_namespace_b.TableInNestedNS.reader.vTableGetNullable(_bc, _bcOffset, 4);
+  EnumInNestedNS get fooEnum => EnumInNestedNS.fromValue(const fb.Int8Reader().vTableGet(_bc, _bcOffset, 6, 0));
+  UnionInNestedNSTypeId? get fooUnionType => UnionInNestedNSTypeId._createOrNull(const fb.Uint8Reader().vTableGetNullable(_bc, _bcOffset, 8));
+  dynamic? get fooUnion {
     switch (fooUnionType?.value) {
-      case 1: return TableInNestedNS.reader.vTableGet(_bc, _bcOffset, 10, null);
+      case 1: return TableInNestedNS.reader.vTableGetNullable(_bc, _bcOffset, 10);
       default: return null;
     }
   }
-  namespace_a_namespace_b.StructInNestedNS get fooStruct => namespace_a_namespace_b.StructInNestedNS.reader.vTableGet(_bc, _bcOffset, 12, null);
+  namespace_a_namespace_b.StructInNestedNS? get fooStruct => namespace_a_namespace_b.StructInNestedNS.reader.vTableGetNullable(_bc, _bcOffset, 12);
 
   @override
   String toString() {
@@ -43,42 +43,36 @@ class TableInFirstNS {
       fooUnion: fooUnion,
       fooStruct: fooStruct?.unpack());
 
-  static int pack(fb.Builder fbBuilder, TableInFirstNST object) {
+  static int pack(fb.Builder fbBuilder, TableInFirstNST? object) {
     if (object == null) return 0;
     return object.pack(fbBuilder);
   }
 }
 
 class TableInFirstNST {
-  namespace_a_namespace_b.TableInNestedNST fooTable;
+  namespace_a_namespace_b.TableInNestedNST? fooTable;
   EnumInNestedNS fooEnum;
-  UnionInNestedNSTypeId fooUnionType;
-  dynamic fooUnion;
-  namespace_a_namespace_b.StructInNestedNST fooStruct;
+  UnionInNestedNSTypeId? fooUnionType;
+  dynamic? fooUnion;
+  namespace_a_namespace_b.StructInNestedNST? fooStruct;
 
   TableInFirstNST({
       this.fooTable,
-      this.fooEnum,
+      this.fooEnum = EnumInNestedNS.A,
       this.fooUnionType,
       this.fooUnion,
       this.fooStruct});
 
   int pack(fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-    final int fooTableOffset = fooTable?.pack(fbBuilder);
-    final int fooUnionOffset = fooUnion?.pack(fbBuilder);
-
+    final int? fooTableOffset = fooTable?.pack(fbBuilder);
+    final int? fooUnionOffset = fooUnion?.pack(fbBuilder);
     fbBuilder.startTable();
-    if (fooTableOffset != null) {
-      fbBuilder.addOffset(0, fooTableOffset);
-    }
-    fbBuilder.addInt8(1, fooEnum?.value);
+    fbBuilder.addOffset(0, fooTableOffset);
+    fbBuilder.addInt8(1, fooEnum.value);
     fbBuilder.addUint8(2, fooUnionType?.value);
-    if (fooUnionOffset != null) {
-      fbBuilder.addOffset(3, fooUnionOffset);
-    }
+    fbBuilder.addOffset(3, fooUnionOffset);
     if (fooStruct != null) {
-      fbBuilder.addStruct(4, fooStruct.pack(fbBuilder));
+      fbBuilder.addStruct(4, fooStruct!.pack(fbBuilder));
     }
     return fbBuilder.endTable();
   }
@@ -98,9 +92,7 @@ class _TableInFirstNSReader extends fb.TableReader<TableInFirstNS> {
 }
 
 class TableInFirstNSBuilder {
-  TableInFirstNSBuilder(this.fbBuilder) {
-    assert(fbBuilder != null);
-  }
+  TableInFirstNSBuilder(this.fbBuilder) {}
 
   final fb.Builder fbBuilder;
 
@@ -108,19 +100,19 @@ class TableInFirstNSBuilder {
     fbBuilder.startTable();
   }
 
-  int addFooTableOffset(int offset) {
+  int addFooTableOffset(int? offset) {
     fbBuilder.addOffset(0, offset);
     return fbBuilder.offset;
   }
-  int addFooEnum(EnumInNestedNS fooEnum) {
+  int addFooEnum(EnumInNestedNS? fooEnum) {
     fbBuilder.addInt8(1, fooEnum?.value);
     return fbBuilder.offset;
   }
-  int addFooUnionType(UnionInNestedNSTypeId fooUnionType) {
+  int addFooUnionType(UnionInNestedNSTypeId? fooUnionType) {
     fbBuilder.addUint8(2, fooUnionType?.value);
     return fbBuilder.offset;
   }
-  int addFooUnionOffset(int offset) {
+  int addFooUnionOffset(int? offset) {
     fbBuilder.addOffset(3, offset);
     return fbBuilder.offset;
   }
@@ -135,18 +127,18 @@ class TableInFirstNSBuilder {
 }
 
 class TableInFirstNSObjectBuilder extends fb.ObjectBuilder {
-  final namespace_a_namespace_b.TableInNestedNSObjectBuilder _fooTable;
-  final EnumInNestedNS _fooEnum;
-  final UnionInNestedNSTypeId _fooUnionType;
-  final dynamic _fooUnion;
-  final namespace_a_namespace_b.StructInNestedNSObjectBuilder _fooStruct;
+  final namespace_a_namespace_b.TableInNestedNSObjectBuilder? _fooTable;
+  final EnumInNestedNS? _fooEnum;
+  final UnionInNestedNSTypeId? _fooUnionType;
+  final dynamic? _fooUnion;
+  final namespace_a_namespace_b.StructInNestedNSObjectBuilder? _fooStruct;
 
   TableInFirstNSObjectBuilder({
-    namespace_a_namespace_b.TableInNestedNSObjectBuilder fooTable,
-    EnumInNestedNS fooEnum,
-    UnionInNestedNSTypeId fooUnionType,
-    dynamic fooUnion,
-    namespace_a_namespace_b.StructInNestedNSObjectBuilder fooStruct,
+    namespace_a_namespace_b.TableInNestedNSObjectBuilder? fooTable,
+    EnumInNestedNS? fooEnum,
+    UnionInNestedNSTypeId? fooUnionType,
+    dynamic? fooUnion,
+    namespace_a_namespace_b.StructInNestedNSObjectBuilder? fooStruct,
   })
       : _fooTable = fooTable,
         _fooEnum = fooEnum,
@@ -156,30 +148,23 @@ class TableInFirstNSObjectBuilder extends fb.ObjectBuilder {
 
   /// Finish building, and store into the [fbBuilder].
   @override
-  int finish(
-    fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-    final int fooTableOffset = _fooTable?.getOrCreateOffset(fbBuilder);
-    final int fooUnionOffset = _fooUnion?.getOrCreateOffset(fbBuilder);
-
+  int finish(fb.Builder fbBuilder) {
+    final int? fooTableOffset = _fooTable?.getOrCreateOffset(fbBuilder);
+    final int? fooUnionOffset = _fooUnion?.getOrCreateOffset(fbBuilder);
     fbBuilder.startTable();
-    if (fooTableOffset != null) {
-      fbBuilder.addOffset(0, fooTableOffset);
-    }
+    fbBuilder.addOffset(0, fooTableOffset);
     fbBuilder.addInt8(1, _fooEnum?.value);
     fbBuilder.addUint8(2, _fooUnionType?.value);
-    if (fooUnionOffset != null) {
-      fbBuilder.addOffset(3, fooUnionOffset);
-    }
+    fbBuilder.addOffset(3, fooUnionOffset);
     if (_fooStruct != null) {
-      fbBuilder.addStruct(4, _fooStruct.finish(fbBuilder));
+      fbBuilder.addStruct(4, _fooStruct!.finish(fbBuilder));
     }
     return fbBuilder.endTable();
   }
 
   /// Convenience method to serialize to byte list.
   @override
-  Uint8List toBytes([String fileIdentifier]) {
+  Uint8List toBytes([String? fileIdentifier]) {
     fb.Builder fbBuilder = new fb.Builder();
     int offset = finish(fbBuilder);
     return fbBuilder.finish(offset, fileIdentifier);
@@ -197,7 +182,7 @@ class SecondTableInA {
   final fb.BufferContext _bc;
   final int _bcOffset;
 
-  namespace_c.TableInC get referToC => namespace_c.TableInC.reader.vTableGet(_bc, _bcOffset, 4, null);
+  namespace_c.TableInC? get referToC => namespace_c.TableInC.reader.vTableGetNullable(_bc, _bcOffset, 4);
 
   @override
   String toString() {
@@ -207,26 +192,22 @@ class SecondTableInA {
   SecondTableInAT unpack() => SecondTableInAT(
       referToC: referToC?.unpack());
 
-  static int pack(fb.Builder fbBuilder, SecondTableInAT object) {
+  static int pack(fb.Builder fbBuilder, SecondTableInAT? object) {
     if (object == null) return 0;
     return object.pack(fbBuilder);
   }
 }
 
 class SecondTableInAT {
-  namespace_c.TableInCT referToC;
+  namespace_c.TableInCT? referToC;
 
   SecondTableInAT({
       this.referToC});
 
   int pack(fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-    final int referToCOffset = referToC?.pack(fbBuilder);
-
+    final int? referToCOffset = referToC?.pack(fbBuilder);
     fbBuilder.startTable();
-    if (referToCOffset != null) {
-      fbBuilder.addOffset(0, referToCOffset);
-    }
+    fbBuilder.addOffset(0, referToCOffset);
     return fbBuilder.endTable();
   }
 
@@ -245,9 +226,7 @@ class _SecondTableInAReader extends fb.TableReader<SecondTableInA> {
 }
 
 class SecondTableInABuilder {
-  SecondTableInABuilder(this.fbBuilder) {
-    assert(fbBuilder != null);
-  }
+  SecondTableInABuilder(this.fbBuilder) {}
 
   final fb.Builder fbBuilder;
 
@@ -255,7 +234,7 @@ class SecondTableInABuilder {
     fbBuilder.startTable();
   }
 
-  int addReferToCOffset(int offset) {
+  int addReferToCOffset(int? offset) {
     fbBuilder.addOffset(0, offset);
     return fbBuilder.offset;
   }
@@ -266,30 +245,25 @@ class SecondTableInABuilder {
 }
 
 class SecondTableInAObjectBuilder extends fb.ObjectBuilder {
-  final namespace_c.TableInCObjectBuilder _referToC;
+  final namespace_c.TableInCObjectBuilder? _referToC;
 
   SecondTableInAObjectBuilder({
-    namespace_c.TableInCObjectBuilder referToC,
+    namespace_c.TableInCObjectBuilder? referToC,
   })
       : _referToC = referToC;
 
   /// Finish building, and store into the [fbBuilder].
   @override
-  int finish(
-    fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-    final int referToCOffset = _referToC?.getOrCreateOffset(fbBuilder);
-
+  int finish(fb.Builder fbBuilder) {
+    final int? referToCOffset = _referToC?.getOrCreateOffset(fbBuilder);
     fbBuilder.startTable();
-    if (referToCOffset != null) {
-      fbBuilder.addOffset(0, referToCOffset);
-    }
+    fbBuilder.addOffset(0, referToCOffset);
     return fbBuilder.endTable();
   }
 
   /// Convenience method to serialize to byte list.
   @override
-  Uint8List toBytes([String fileIdentifier]) {
+  Uint8List toBytes([String? fileIdentifier]) {
     fb.Builder fbBuilder = new fb.Builder();
     int offset = finish(fbBuilder);
     return fbBuilder.finish(offset, fileIdentifier);
diff --git a/tests/namespace_test/namespace_test2_namespace_c_generated.dart b/tests/namespace_test/namespace_test2_namespace_c_generated.dart
index 41f474c3872..a82f2c4ab2e 100644
--- a/tests/namespace_test/namespace_test2_namespace_c_generated.dart
+++ b/tests/namespace_test/namespace_test2_namespace_c_generated.dart
@@ -1,5 +1,5 @@
 // automatically generated by the FlatBuffers compiler, do not modify
-// ignore_for_file: unused_import, unused_field, unused_local_variable
+// ignore_for_file: unused_import, unused_field, unused_element, unused_local_variable
 
 library namespace_c;
 
@@ -20,8 +20,8 @@ class TableInC {
   final fb.BufferContext _bc;
   final int _bcOffset;
 
-  namespace_a.TableInFirstNS get referToA1 => namespace_a.TableInFirstNS.reader.vTableGet(_bc, _bcOffset, 4, null);
-  namespace_a.SecondTableInA get referToA2 => namespace_a.SecondTableInA.reader.vTableGet(_bc, _bcOffset, 6, null);
+  namespace_a.TableInFirstNS? get referToA1 => namespace_a.TableInFirstNS.reader.vTableGetNullable(_bc, _bcOffset, 4);
+  namespace_a.SecondTableInA? get referToA2 => namespace_a.SecondTableInA.reader.vTableGetNullable(_bc, _bcOffset, 6);
 
   @override
   String toString() {
@@ -32,32 +32,26 @@ class TableInC {
       referToA1: referToA1?.unpack(),
       referToA2: referToA2?.unpack());
 
-  static int pack(fb.Builder fbBuilder, TableInCT object) {
+  static int pack(fb.Builder fbBuilder, TableInCT? object) {
     if (object == null) return 0;
     return object.pack(fbBuilder);
   }
 }
 
 class TableInCT {
-  namespace_a.TableInFirstNST referToA1;
-  namespace_a.SecondTableInAT referToA2;
+  namespace_a.TableInFirstNST? referToA1;
+  namespace_a.SecondTableInAT? referToA2;
 
   TableInCT({
       this.referToA1,
       this.referToA2});
 
   int pack(fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-    final int referToA1Offset = referToA1?.pack(fbBuilder);
-    final int referToA2Offset = referToA2?.pack(fbBuilder);
-
+    final int? referToA1Offset = referToA1?.pack(fbBuilder);
+    final int? referToA2Offset = referToA2?.pack(fbBuilder);
     fbBuilder.startTable();
-    if (referToA1Offset != null) {
-      fbBuilder.addOffset(0, referToA1Offset);
-    }
-    if (referToA2Offset != null) {
-      fbBuilder.addOffset(1, referToA2Offset);
-    }
+    fbBuilder.addOffset(0, referToA1Offset);
+    fbBuilder.addOffset(1, referToA2Offset);
     return fbBuilder.endTable();
   }
 
@@ -76,9 +70,7 @@ class _TableInCReader extends fb.TableReader<TableInC> {
 }
 
 class TableInCBuilder {
-  TableInCBuilder(this.fbBuilder) {
-    assert(fbBuilder != null);
-  }
+  TableInCBuilder(this.fbBuilder) {}
 
   final fb.Builder fbBuilder;
 
@@ -86,11 +78,11 @@ class TableInCBuilder {
     fbBuilder.startTable();
   }
 
-  int addReferToA1Offset(int offset) {
+  int addReferToA1Offset(int? offset) {
     fbBuilder.addOffset(0, offset);
     return fbBuilder.offset;
   }
-  int addReferToA2Offset(int offset) {
+  int addReferToA2Offset(int? offset) {
     fbBuilder.addOffset(1, offset);
     return fbBuilder.offset;
   }
@@ -101,37 +93,30 @@ class TableInCBuilder {
 }
 
 class TableInCObjectBuilder extends fb.ObjectBuilder {
-  final namespace_a.TableInFirstNSObjectBuilder _referToA1;
-  final namespace_a.SecondTableInAObjectBuilder _referToA2;
+  final namespace_a.TableInFirstNSObjectBuilder? _referToA1;
+  final namespace_a.SecondTableInAObjectBuilder? _referToA2;
 
   TableInCObjectBuilder({
-    namespace_a.TableInFirstNSObjectBuilder referToA1,
-    namespace_a.SecondTableInAObjectBuilder referToA2,
+    namespace_a.TableInFirstNSObjectBuilder? referToA1,
+    namespace_a.SecondTableInAObjectBuilder? referToA2,
   })
       : _referToA1 = referToA1,
         _referToA2 = referToA2;
 
   /// Finish building, and store into the [fbBuilder].
   @override
-  int finish(
-    fb.Builder fbBuilder) {
-    assert(fbBuilder != null);
-    final int referToA1Offset = _referToA1?.getOrCreateOffset(fbBuilder);
-    final int referToA2Offset = _referToA2?.getOrCreateOffset(fbBuilder);
-
+  int finish(fb.Builder fbBuilder) {
+    final int? referToA1Offset = _referToA1?.getOrCreateOffset(fbBuilder);
+    final int? referToA2Offset = _referToA2?.getOrCreateOffset(fbBuilder);
     fbBuilder.startTable();
-    if (referToA1Offset != null) {
-      fbBuilder.addOffset(0, referToA1Offset);
-    }
-    if (referToA2Offset != null) {
-      fbBuilder.addOffset(1, referToA2Offset);
-    }
+    fbBuilder.addOffset(0, referToA1Offset);
+    fbBuilder.addOffset(1, referToA2Offset);
     return fbBuilder.endTable();
   }
 
   /// Convenience method to serialize to byte list.
   @override
-  Uint8List toBytes([String fileIdentifier]) {
+  Uint8List toBytes([String? fileIdentifier]) {
     fb.Builder fbBuilder = new fb.Builder();
     int offset = finish(fbBuilder);
     return fbBuilder.finish(offset, fileIdentifier);