diff --git a/src/main/java/com/plugatar/jkscope/JKScope.java b/src/main/java/com/plugatar/jkscope/JKScope.java
index 8cd6745..1bccf55 100644
--- a/src/main/java/com/plugatar/jkscope/JKScope.java
+++ b/src/main/java/com/plugatar/jkscope/JKScope.java
@@ -137,33 +137,33 @@ public interface JKScope<V extends JKScope<V>> extends BaseScope<V, V> {
   @Override
   default V also(final ThConsumer<? super V, ?> block) {
     blockArgNotNull(block);
-    block.asUnchecked().accept(uncheckedCast(this));
+    ThConsumer.unchecked(block).accept(uncheckedCast(this));
     return uncheckedCast(this);
   }
 
   @Override
   default V letIt(final ThConsumer<? super V, ?> block) {
     blockArgNotNull(block);
-    block.asUnchecked().accept(uncheckedCast(this));
+    ThConsumer.unchecked(block).accept(uncheckedCast(this));
     return uncheckedCast(this);
   }
 
   @Override
   default <R> R letOut(final ThFunction<? super V, ? extends R, ?> block) {
     blockArgNotNull(block);
-    return block.asUnchecked().apply(uncheckedCast(this));
+    return ThFunction.unchecked(block).apply(uncheckedCast(this));
   }
 
   @Override
   default <R> Opt<R> letOpt(final ThFunction<? super V, ? extends R, ?> block) {
     blockArgNotNull(block);
-    return Opt.of(block.asUnchecked().apply(uncheckedCast(this)));
+    return Opt.of(ThFunction.unchecked(block).apply(uncheckedCast(this)));
   }
 
   @Override
   default Opt<V> takeIf(final ThPredicate<? super V, ?> block) {
     blockArgNotNull(block);
-    return block.asUnchecked().test(uncheckedCast(this))
+    return ThPredicate.unchecked(block).test(uncheckedCast(this))
       ? Opt.of(uncheckedCast(this))
       : Opt.empty();
   }
@@ -171,7 +171,7 @@ default Opt<V> takeIf(final ThPredicate<? super V, ?> block) {
   @Override
   default Opt<V> takeUnless(final ThPredicate<? super V, ?> block) {
     blockArgNotNull(block);
-    return block.asUnchecked().test(uncheckedCast(this))
+    return ThPredicate.unchecked(block).test(uncheckedCast(this))
       ? Opt.empty()
       : Opt.of(uncheckedCast(this));
   }
@@ -189,7 +189,7 @@ default Opt<V> takeUnless(final ThPredicate<? super V, ?> block) {
    */
   static void run(final ThRunnable<?> block) {
     blockArgNotNull(block);
-    block.asUnchecked().run();
+    ThRunnable.unchecked(block).run();
   }
 
   /**
@@ -208,7 +208,7 @@ static void run(final ThRunnable<?> block) {
   static void runCatching(final ThRunnable<?> block) {
     blockArgNotNull(block);
     try {
-      block.asUnchecked().run();
+      block.run();
     } catch (final Throwable ignored) { }
   }
 
@@ -229,7 +229,7 @@ static void runRec(final ThConsumer<ThRunnable<Throwable>, ?> block) {
     blockArgNotNull(block);
     final AtomicReference<ThRunnable<Throwable>> selfRef = new AtomicReference<>();
     selfRef.set(() -> block.accept(selfRef.get()));
-    block.asUnchecked().accept(selfRef.get());
+    ThConsumer.unchecked(block).accept(selfRef.get());
   }
 
   /**
@@ -248,7 +248,7 @@ static void runRec(final ThConsumer<ThRunnable<Throwable>, ?> block) {
   static <V> void with(final V value,
                        final ThConsumer<? super V, ?> block) {
     blockArgNotNull(block);
-    block.asUnchecked().accept(value);
+    ThConsumer.unchecked(block).accept(value);
   }
 
   /**
@@ -266,7 +266,7 @@ static <V> void with(final V value,
   static void withInt(final int value,
                       final ThIntConsumer<?> block) {
     blockArgNotNull(block);
-    block.asUnchecked().accept(value);
+    ThIntConsumer.unchecked(block).accept(value);
   }
 
   /**
@@ -284,7 +284,7 @@ static void withInt(final int value,
   static void withLong(final long value,
                        final ThLongConsumer<?> block) {
     blockArgNotNull(block);
-    block.asUnchecked().accept(value);
+    ThLongConsumer.unchecked(block).accept(value);
   }
 
   /**
@@ -302,7 +302,7 @@ static void withLong(final long value,
   static void withDouble(final double value,
                          final ThDoubleConsumer<?> block) {
     blockArgNotNull(block);
-    block.asUnchecked().accept(value);
+    ThDoubleConsumer.unchecked(block).accept(value);
   }
 
   /**
@@ -319,11 +319,11 @@ static void withDouble(final double value,
   static <V extends AutoCloseable> void withResource(final V value,
                                                      final ThConsumer<? super V, ?> block) {
     blockArgNotNull(block);
-    ((ThBiConsumer<V, ThConsumer<? super V, ?>, Throwable>) (v, b) -> {
+    ThBiConsumer.<V, ThConsumer<? super V, ?>>unchecked((v, b) -> {
       try (final V resource = v) {
         b.accept(resource);
       }
-    }).asUnchecked().accept(value, block);
+    }).accept(value, block);
   }
 
   /**
@@ -345,7 +345,7 @@ static <V1, V2> void with(final V1 value1,
                             final V2 value2,
                             final ThBiConsumer<? super V1, ? super V2, ?> block) {
     blockArgNotNull(block);
-    block.asUnchecked().accept(value1, value2);
+    ThBiConsumer.unchecked(block).accept(value1, value2);
   }
 
   /**
@@ -370,7 +370,7 @@ static <V1, V2, V3> void with(final V1 value1,
                                 final V3 value3,
                                 final ThTriConsumer<? super V1, ? super V2, ? super V3, ?> block) {
     blockArgNotNull(block);
-    block.asUnchecked().accept(value1, value2, value3);
+    ThTriConsumer.unchecked(block).accept(value1, value2, value3);
   }
 
   /**
@@ -418,7 +418,7 @@ static <V> Opt<V> letNonNull(final V value) {
    */
   static <V> V let(final ThSupplier<? extends V, ?> block) {
     blockArgNotNull(block);
-    return block.asUnchecked().get();
+    return ThSupplier.unchecked(block).get();
   }
 
   /**
@@ -436,7 +436,7 @@ static <V> V let(final ThSupplier<? extends V, ?> block) {
    */
   static int letInt(final ThIntSupplier<?> block) {
     blockArgNotNull(block);
-    return block.asUnchecked().get();
+    return ThIntSupplier.unchecked(block).get();
   }
 
   /**
@@ -454,7 +454,7 @@ static int letInt(final ThIntSupplier<?> block) {
    */
   static long letLong(final ThLongSupplier<?> block) {
     blockArgNotNull(block);
-    return block.asUnchecked().get();
+    return ThLongSupplier.unchecked(block).get();
   }
 
   /**
@@ -472,7 +472,7 @@ static long letLong(final ThLongSupplier<?> block) {
    */
   static double letDouble(final ThDoubleSupplier<?> block) {
     blockArgNotNull(block);
-    return block.asUnchecked().get();
+    return ThDoubleSupplier.unchecked(block).get();
   }
 
   /**
@@ -492,7 +492,7 @@ static double letDouble(final ThDoubleSupplier<?> block) {
   static <V> V let(final V value,
                    final ThConsumer<? super V, ?> block) {
     blockArgNotNull(block);
-    block.asUnchecked().accept(value);
+    ThConsumer.unchecked(block).accept(value);
     return value;
   }
 
@@ -512,7 +512,7 @@ static <V> V let(final V value,
   static int letInt(final int value,
                     final ThIntConsumer<?> block) {
     blockArgNotNull(block);
-    block.asUnchecked().accept(value);
+    ThIntConsumer.unchecked(block).accept(value);
     return value;
   }
 
@@ -532,7 +532,7 @@ static int letInt(final int value,
   static long letLong(final long value,
                       final ThLongConsumer<?> block) {
     blockArgNotNull(block);
-    block.asUnchecked().accept(value);
+    ThLongConsumer.unchecked(block).accept(value);
     return value;
   }
 
@@ -552,7 +552,7 @@ static long letLong(final long value,
   static double letDouble(final double value,
                           final ThDoubleConsumer<?> block) {
     blockArgNotNull(block);
-    block.asUnchecked().accept(value);
+    ThDoubleConsumer.unchecked(block).accept(value);
     return value;
   }
 
@@ -578,7 +578,7 @@ static <V> V letRec(final V initialValue,
     blockArgNotNull(block);
     final AtomicReference<ThFunction<V, V, Throwable>> selfRef = new AtomicReference<>();
     selfRef.set(v -> block.apply(v, selfRef.get()));
-    return block.asUnchecked().apply(initialValue, selfRef.get());
+    return ThBiFunction.unchecked(block).apply(initialValue, selfRef.get());
   }
 
   /**
@@ -602,7 +602,7 @@ static int letIntRec(final int initialValue,
     blockArgNotNull(block);
     final AtomicReference<ThIntToIntFunction<Throwable>> selfRef = new AtomicReference<>();
     selfRef.set(v -> block.apply(v, selfRef.get()));
-    return block.asUnchecked().apply(initialValue, selfRef.get());
+    return ThIntObjToIntFunction.unchecked(block).apply(initialValue, selfRef.get());
   }
 
   /**
@@ -626,7 +626,7 @@ static long letLongRec(final long initialValue,
     blockArgNotNull(block);
     final AtomicReference<ThLongToLongFunction<Throwable>> selfRef = new AtomicReference<>();
     selfRef.set(v -> block.apply(v, selfRef.get()));
-    return block.asUnchecked().apply(initialValue, selfRef.get());
+    return ThLongObjToLongFunction.unchecked(block).apply(initialValue, selfRef.get());
   }
 
   /**
@@ -650,7 +650,7 @@ static double letDoubleRec(final double initialValue,
     blockArgNotNull(block);
     final AtomicReference<ThDoubleToDoubleFunction<Throwable>> selfRef = new AtomicReference<>();
     selfRef.set(v -> block.apply(v, selfRef.get()));
-    return block.asUnchecked().apply(initialValue, selfRef.get());
+    return ThDoubleObjToDoubleFunction.unchecked(block).apply(initialValue, selfRef.get());
   }
 
   /**
@@ -672,7 +672,7 @@ static double letDoubleRec(final double initialValue,
   static <V, R> R letWith(final V value,
                           final ThFunction<? super V, ? extends R, ?> block) {
     blockArgNotNull(block);
-    return block.asUnchecked().apply(value);
+    return ThFunction.unchecked(block).apply(value);
   }
 
   /**
@@ -692,7 +692,7 @@ static <V, R> R letWith(final V value,
   static <V> int letIntWith(final V value,
                             final ThToIntFunction<? super V, ?> block) {
     blockArgNotNull(block);
-    return block.asUnchecked().apply(value);
+    return ThToIntFunction.unchecked(block).apply(value);
   }
 
   /**
@@ -712,7 +712,7 @@ static <V> int letIntWith(final V value,
   static <V> long letLongWith(final V value,
                               final ThToLongFunction<? super V, ?> block) {
     blockArgNotNull(block);
-    return block.asUnchecked().apply(value);
+    return ThToLongFunction.unchecked(block).apply(value);
   }
 
   /**
@@ -732,7 +732,7 @@ static <V> long letLongWith(final V value,
   static <V> double letDoubleWith(final V value,
                                   final ThToDoubleFunction<? super V, ?> block) {
     blockArgNotNull(block);
-    return block.asUnchecked().apply(value);
+    return ThToDoubleFunction.unchecked(block).apply(value);
   }
 
   /**
@@ -751,11 +751,11 @@ static <V> double letDoubleWith(final V value,
   static <V extends AutoCloseable, R> R letWithResource(final V value,
                                                         final ThFunction<? super V, ? extends R, ?> block) {
     blockArgNotNull(block);
-    return ((ThBiFunction<V, ThFunction<? super V, ? extends R, ?>, R, Throwable>) (v, b) -> {
+    return ThBiFunction.<V, ThFunction<? super V, ? extends R, ?>, R>unchecked((v, b) -> {
       try (final V resource = v) {
         return b.apply(resource);
       }
-    }).asUnchecked().apply(value, block);
+    }).apply(value, block);
   }
 
   /**
@@ -781,7 +781,7 @@ static <V1, V2, R> R letWith(final V1 value1,
                                final V2 value2,
                                final ThBiFunction<? super V1, ? super V2, ? extends R, ?> block) {
     blockArgNotNull(block);
-    return block.asUnchecked().apply(value1, value2);
+    return ThBiFunction.unchecked(block).apply(value1, value2);
   }
 
   /**
@@ -811,7 +811,7 @@ static <V1, V2, V3, R> R letWith(final V1 value1,
                                    final V3 value3,
                                    final ThTriFunction<? super V1, ? super V2, ? super V3, ? extends R, ?> block) {
     blockArgNotNull(block);
-    return block.asUnchecked().apply(value1, value2, value3);
+    return ThTriFunction.unchecked(block).apply(value1, value2, value3);
   }
 
   /**
diff --git a/src/main/java/com/plugatar/jkscope/Lazy.java b/src/main/java/com/plugatar/jkscope/Lazy.java
index 09a2de6..071798b 100644
--- a/src/main/java/com/plugatar/jkscope/Lazy.java
+++ b/src/main/java/com/plugatar/jkscope/Lazy.java
@@ -38,34 +38,34 @@ public interface Lazy<V> extends ThSupplier<V, RuntimeException>, BaseScope<V, L
   @Override
   default Lazy<V> also(final ThConsumer<? super V, ?> block) {
     blockArgNotNull(block);
-    block.asUnchecked().accept(this.get());
+    ThConsumer.unchecked(block).accept(this.get());
     return this;
   }
 
   @Override
   default Lazy<V> letIt(final ThConsumer<? super V, ?> block) {
     blockArgNotNull(block);
-    block.asUnchecked().accept(this.get());
+    ThConsumer.unchecked(block).accept(this.get());
     return this;
   }
 
   @Override
   default <R> R letOut(final ThFunction<? super V, ? extends R, ?> block) {
     blockArgNotNull(block);
-    return block.asUnchecked().apply(this.get());
+    return ThFunction.unchecked(block).apply(this.get());
   }
 
   @Override
   default <R> Opt<R> letOpt(final ThFunction<? super V, ? extends R, ?> block) {
     blockArgNotNull(block);
-    return Opt.of(block.asUnchecked().apply(this.get()));
+    return Opt.of(ThFunction.unchecked(block).apply(this.get()));
   }
 
   @Override
   default Opt<V> takeIf(final ThPredicate<? super V, ?> block) {
     blockArgNotNull(block);
     final V v = this.get();
-    return block.asUnchecked().test(v)
+    return ThPredicate.unchecked(block).test(v)
       ? Opt.of(v)
       : Opt.empty();
   }
@@ -74,7 +74,7 @@ default Opt<V> takeIf(final ThPredicate<? super V, ?> block) {
   default Opt<V> takeUnless(final ThPredicate<? super V, ?> block) {
     blockArgNotNull(block);
     final V v = this.get();
-    return block.asUnchecked().test(v)
+    return ThPredicate.unchecked(block).test(v)
       ? Opt.empty()
       : Opt.of(v);
   }
@@ -210,7 +210,7 @@ public V get() {
         if (v2 != UNINITIALIZED_VALUE) {
           return uncheckedCast(v2);
         }
-        final V newValue = this.initializer.asUnchecked().get();
+        final V newValue = ThSupplier.unchecked(this.initializer).get();
         this.value = newValue;
         this.initializer = null;
         return newValue;
@@ -264,7 +264,7 @@ public V get() {
       }
       final ThSupplier<? extends V, ?> init = this.initializer;
       if (init != null) {
-        final V newValue = init.asUnchecked().get();
+        final V newValue = ThSupplier.unchecked(init).get();
         if (VALUE_UPDATER.compareAndSet(this, UNINITIALIZED_VALUE, newValue)) {
           this.initializer = null;
           return newValue;
@@ -318,7 +318,7 @@ public V get() {
       }
       final ThSupplier<? extends V, ?> init = this.initializer;
       if (init != null) {
-        final V newValue = init.asUnchecked().get();
+        final V newValue = ThSupplier.unchecked(init).get();
         this.value = newValue;
         this.initializer = null;
         return newValue;
diff --git a/src/main/java/com/plugatar/jkscope/Opt.java b/src/main/java/com/plugatar/jkscope/Opt.java
index f37c57c..32b8803 100644
--- a/src/main/java/com/plugatar/jkscope/Opt.java
+++ b/src/main/java/com/plugatar/jkscope/Opt.java
@@ -165,33 +165,33 @@ private Of(final V value) {
     @Override
     public Opt<V> also(final ThConsumer<? super V, ?> block) {
       blockArgNotNull(block);
-      block.asUnchecked().accept(this.value);
+      ThConsumer.unchecked(block).accept(this.value);
       return this;
     }
 
     @Override
     public Opt<V> letIt(final ThConsumer<? super V, ?> block) {
       blockArgNotNull(block);
-      block.asUnchecked().accept(this.value);
+      ThConsumer.unchecked(block).accept(this.value);
       return this;
     }
 
     @Override
     public <R> R letOut(final ThFunction<? super V, ? extends R, ?> block) {
       blockArgNotNull(block);
-      return block.asUnchecked().apply(this.value);
+      return ThFunction.unchecked(block).apply(this.value);
     }
 
     @Override
     public <R> Opt<R> letOpt(final ThFunction<? super V, ? extends R, ?> block) {
       blockArgNotNull(block);
-      return Opt.of(block.asUnchecked().apply(this.value));
+      return Opt.of(ThFunction.unchecked(block).apply(this.value));
     }
 
     @Override
     public Opt<V> takeIf(final ThPredicate<? super V, ?> block) {
       blockArgNotNull(block);
-      return block.asUnchecked().test(this.value)
+      return ThPredicate.unchecked(block).test(this.value)
         ? this
         : Opt.empty();
     }
@@ -199,7 +199,7 @@ public Opt<V> takeIf(final ThPredicate<? super V, ?> block) {
     @Override
     public Opt<V> takeUnless(final ThPredicate<? super V, ?> block) {
       blockArgNotNull(block);
-      return block.asUnchecked().test(this.value)
+      return ThPredicate.unchecked(block).test(this.value)
         ? Opt.empty()
         : this;
     }
@@ -320,9 +320,7 @@ public Opt<V> takeNonNull() {
     @Override
     public Opt<V> throwIfEmpty(final ThSupplier<? extends Throwable, ?> block) {
       blockArgNotNull(block);
-      return ((ThFunction<ThSupplier<? extends Throwable, ?>, Opt<V>, ?>) it -> { throw it.get(); })
-        .asUnchecked()
-        .apply(block);
+      return ThFunction.<ThSupplier<? extends Throwable, ?>, Opt<V>>unchecked(it -> { throw it.get(); }).apply(block);
     }
 
     @Override
@@ -348,15 +346,13 @@ public V orNull() {
     @Override
     public V orElseGet(final ThSupplier<? extends V, ?> block) {
       blockArgNotNull(block);
-      return block.asUnchecked().get();
+      return ThSupplier.unchecked(block).get();
     }
 
     @Override
     public V orElseThrow(final ThSupplier<? extends Throwable, ?> block) {
       blockArgNotNull(block);
-      return ((ThFunction<ThSupplier<? extends Throwable, ?>, V, ?>) it -> { throw it.get(); })
-        .asUnchecked()
-        .apply(block);
+      return ThFunction.<ThSupplier<? extends Throwable, ?>, V>unchecked(it -> { throw it.get(); }).apply(block);
     }
 
     @Override
diff --git a/src/main/java/com/plugatar/jkscope/function/ThBiConsumer.java b/src/main/java/com/plugatar/jkscope/function/ThBiConsumer.java
index 94cb4f8..191761e 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThBiConsumer.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThBiConsumer.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link java.util.function.BiConsumer} specialization that might throw an exception.
  *
@@ -36,12 +39,16 @@ public interface ThBiConsumer<T, U, E extends Throwable> {
   void accept(T t, U u) throws E;
 
   /**
-   * Returns this consumer as an unchecked consumer.
+   * Returns given consumer as an unchecked consumer.
    *
+   * @param origin the origin consumer
+   * @param <T>    the type of the first input argument
+   * @param <U>    the type of the second input argument
    * @return unchecked consumer
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThBiConsumer<T, U, RuntimeException> asUnchecked() {
-    return (ThBiConsumer<T, U, RuntimeException>) this;
+  static <T, U> ThBiConsumer<T, U, RuntimeException> unchecked(final ThBiConsumer<? super T, ? super U, ?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/ThBiFunction.java b/src/main/java/com/plugatar/jkscope/function/ThBiFunction.java
index 7c58836..ad30c0a 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThBiFunction.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThBiFunction.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link java.util.function.BiFunction} specialization that might throw an exception.
  *
@@ -38,12 +41,17 @@ public interface ThBiFunction<T, U, R, E extends Throwable> {
   R apply(T t, U u) throws E;
 
   /**
-   * Returns this functions as an unchecked functions.
+   * Returns given function as an unchecked function.
    *
+   * @param origin the origin function
+   * @param <T>    the type of the first input argument
+   * @param <U>    the type of the second input argument
+   * @param <R>    the type of the result
    * @return unchecked function
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThBiFunction<T, U, R, RuntimeException> asUnchecked() {
-    return (ThBiFunction<T, U, R, RuntimeException>) this;
+  static <T, U, R> ThBiFunction<T, U, R, RuntimeException> unchecked(final ThBiFunction<? super T, ? super U, ? extends R, ?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/ThConsumer.java b/src/main/java/com/plugatar/jkscope/function/ThConsumer.java
index 2c28e5c..73cc040 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThConsumer.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThConsumer.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link java.util.function.Consumer} specialization that might throw an exception.
  *
@@ -34,12 +37,15 @@ public interface ThConsumer<T, E extends Throwable> {
   void accept(T t) throws E;
 
   /**
-   * Returns this consumer as an unchecked consumer.
+   * Returns given consumer as an unchecked consumer.
    *
+   * @param origin the origin consumer
+   * @param <T>    the type of the input argument
    * @return unchecked consumer
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThConsumer<T, RuntimeException> asUnchecked() {
-    return (ThConsumer<T, RuntimeException>) this;
+  static <T> ThConsumer<T, RuntimeException> unchecked(final ThConsumer<? super T, ?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/ThDoubleConsumer.java b/src/main/java/com/plugatar/jkscope/function/ThDoubleConsumer.java
index f1e9404..0cd53de 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThDoubleConsumer.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThDoubleConsumer.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link java.util.function.Consumer} specialization that that accepts an {@code double}-valued argument and might
  * throw an exception.
@@ -34,12 +37,14 @@ public interface ThDoubleConsumer<E extends Throwable> {
   void accept(double value) throws E;
 
   /**
-   * Returns this consumer as an unchecked consumer.
+   * Returns given consumer as an unchecked consumer.
    *
+   * @param origin the origin consumer
    * @return unchecked consumer
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThDoubleConsumer<RuntimeException> asUnchecked() {
-    return (ThDoubleConsumer<RuntimeException>) this;
+  static ThDoubleConsumer<RuntimeException> unchecked(final ThDoubleConsumer<?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/ThDoubleObjToDoubleFunction.java b/src/main/java/com/plugatar/jkscope/function/ThDoubleObjToDoubleFunction.java
index 5ef7c32..92b2b58 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThDoubleObjToDoubleFunction.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThDoubleObjToDoubleFunction.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link java.util.function.Function} specialization that accepts an object-valued and a {@code double}-valued
  * argument and produces an {@code double}-valued result and might throw an exception.
@@ -37,12 +40,15 @@ public interface ThDoubleObjToDoubleFunction<T, E extends Throwable> {
   double apply(double value, T t) throws E;
 
   /**
-   * Returns this functions as an unchecked functions.
+   * Returns given function as an unchecked function.
    *
+   * @param origin the origin function
+   * @param <T>    the type of the second input argument
    * @return unchecked function
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThDoubleObjToDoubleFunction<T, RuntimeException> asUnchecked() {
-    return (ThDoubleObjToDoubleFunction<T, RuntimeException>) this;
+  static <T> ThDoubleObjToDoubleFunction<T, RuntimeException> unchecked(final ThDoubleObjToDoubleFunction<? super T, ?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/ThDoubleSupplier.java b/src/main/java/com/plugatar/jkscope/function/ThDoubleSupplier.java
index a7fa561..027dcc4 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThDoubleSupplier.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThDoubleSupplier.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link java.util.function.Supplier} specialization that produces an {@code double}-valued result and might throw
  * an exception.
@@ -34,12 +37,14 @@ public interface ThDoubleSupplier<E extends Throwable> {
   double get() throws E;
 
   /**
-   * Returns this supplier as an unchecked supplier.
+   * Returns given supplier as an unchecked supplier.
    *
-   * @return unchecked runnable
+   * @param origin the origin supplier
+   * @return unchecked supplier
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThDoubleSupplier<RuntimeException> asUnchecked() {
-    return (ThDoubleSupplier<RuntimeException>) this;
+  static ThDoubleSupplier<RuntimeException> unchecked(final ThDoubleSupplier<?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/ThDoubleToDoubleFunction.java b/src/main/java/com/plugatar/jkscope/function/ThDoubleToDoubleFunction.java
index b9d4f43..b5bda23 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThDoubleToDoubleFunction.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThDoubleToDoubleFunction.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link java.util.function.Function} specialization that accepts an {@code double}-valued argument and produces an
  * {@code double}-valued result and might throw an exception.
@@ -35,12 +38,14 @@ public interface ThDoubleToDoubleFunction<E extends Throwable> {
   double apply(double value) throws E;
 
   /**
-   * Returns this functions as an unchecked functions.
+   * Returns given function as an unchecked function.
    *
+   * @param origin the origin function
    * @return unchecked function
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThDoubleToDoubleFunction<RuntimeException> asUnchecked() {
-    return (ThDoubleToDoubleFunction<RuntimeException>) this;
+  static ThDoubleToDoubleFunction<RuntimeException> unchecked(final ThDoubleToDoubleFunction<?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/ThFunction.java b/src/main/java/com/plugatar/jkscope/function/ThFunction.java
index f311de9..dfaf15f 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThFunction.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThFunction.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link java.util.function.Function} specialization that might throw an exception.
  *
@@ -36,12 +39,16 @@ public interface ThFunction<T, R, E extends Throwable> {
   R apply(T t) throws E;
 
   /**
-   * Returns this functions as an unchecked functions.
+   * Returns given function as an unchecked function.
    *
+   * @param origin the origin function
+   * @param <T>    the type of the input argument
+   * @param <R>    the type of the result
    * @return unchecked function
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThFunction<T, R, RuntimeException> asUnchecked() {
-    return (ThFunction<T, R, RuntimeException>) this;
+  static <T, R> ThFunction<T, R, RuntimeException> unchecked(final ThFunction<? super T, ? extends R, ?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/ThIntConsumer.java b/src/main/java/com/plugatar/jkscope/function/ThIntConsumer.java
index 96ba73d..f26bd8a 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThIntConsumer.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThIntConsumer.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link java.util.function.Consumer} specialization that that accepts an {@code int}-valued argument and might
  * throw an exception.
@@ -34,12 +37,14 @@ public interface ThIntConsumer<E extends Throwable> {
   void accept(int value) throws E;
 
   /**
-   * Returns this consumer as an unchecked consumer.
+   * Returns given consumer as an unchecked consumer.
    *
+   * @param origin the origin consumer
    * @return unchecked consumer
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThIntConsumer<RuntimeException> asUnchecked() {
-    return (ThIntConsumer<RuntimeException>) this;
+  static ThIntConsumer<RuntimeException> unchecked(final ThIntConsumer<?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/ThIntObjToIntFunction.java b/src/main/java/com/plugatar/jkscope/function/ThIntObjToIntFunction.java
index 7ce5dd3..324d353 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThIntObjToIntFunction.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThIntObjToIntFunction.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link java.util.function.Function} specialization that accepts an object-valued and a {@code int}-valued
  * argument and produces an {@code int}-valued result and might throw an exception.
@@ -37,12 +40,15 @@ public interface ThIntObjToIntFunction<T, E extends Throwable> {
   int apply(int value, T t) throws E;
 
   /**
-   * Returns this functions as an unchecked functions.
+   * Returns given function as an unchecked function.
    *
+   * @param origin the origin function
+   * @param <T>    the type of the second input argument
    * @return unchecked function
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThIntObjToIntFunction<T, RuntimeException> asUnchecked() {
-    return (ThIntObjToIntFunction<T, RuntimeException>) this;
+  static <T> ThIntObjToIntFunction<T, RuntimeException> unchecked(final ThIntObjToIntFunction<? super T, ?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/ThIntSupplier.java b/src/main/java/com/plugatar/jkscope/function/ThIntSupplier.java
index bea468d..f4577eb 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThIntSupplier.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThIntSupplier.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link java.util.function.Supplier} specialization that produces an {@code int}-valued result and might throw an
  * exception.
@@ -34,12 +37,14 @@ public interface ThIntSupplier<E extends Throwable> {
   int get() throws E;
 
   /**
-   * Returns this supplier as an unchecked supplier.
+   * Returns given supplier as an unchecked supplier.
    *
-   * @return unchecked runnable
+   * @param origin the origin supplier
+   * @return unchecked supplier
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThIntSupplier<RuntimeException> asUnchecked() {
-    return (ThIntSupplier<RuntimeException>) this;
+  static ThIntSupplier<RuntimeException> unchecked(final ThIntSupplier<?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/ThIntToIntFunction.java b/src/main/java/com/plugatar/jkscope/function/ThIntToIntFunction.java
index d7358e4..d62f84d 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThIntToIntFunction.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThIntToIntFunction.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link java.util.function.Function} specialization that accepts an {@code int}-valued argument and produces an
  * {@code int}-valued result and might throw an exception.
@@ -35,12 +38,14 @@ public interface ThIntToIntFunction<E extends Throwable> {
   int apply(int value) throws E;
 
   /**
-   * Returns this functions as an unchecked functions.
+   * Returns given function as an unchecked function.
    *
+   * @param origin the origin function
    * @return unchecked function
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThIntToIntFunction<RuntimeException> asUnchecked() {
-    return (ThIntToIntFunction<RuntimeException>) this;
+  static ThIntToIntFunction<RuntimeException> unchecked(final ThIntToIntFunction<?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/ThLongConsumer.java b/src/main/java/com/plugatar/jkscope/function/ThLongConsumer.java
index 981d9cc..dc2e6f2 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThLongConsumer.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThLongConsumer.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link java.util.function.Consumer} specialization that that accepts an {@code long}-valued argument and might
  * throw an exception.
@@ -34,12 +37,14 @@ public interface ThLongConsumer<E extends Throwable> {
   void accept(long value) throws E;
 
   /**
-   * Returns this consumer as an unchecked consumer.
+   * Returns given consumer as an unchecked consumer.
    *
+   * @param origin the origin consumer
    * @return unchecked consumer
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThLongConsumer<RuntimeException> asUnchecked() {
-    return (ThLongConsumer<RuntimeException>) this;
+  static ThLongConsumer<RuntimeException> unchecked(final ThLongConsumer<?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/ThLongObjToLongFunction.java b/src/main/java/com/plugatar/jkscope/function/ThLongObjToLongFunction.java
index 6207c5d..834150f 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThLongObjToLongFunction.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThLongObjToLongFunction.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link java.util.function.Function} specialization that accepts an object-valued and a {@code long}-valued
  * argument and produces an {@code long}-valued result and might throw an exception.
@@ -37,12 +40,15 @@ public interface ThLongObjToLongFunction<T, E extends Throwable> {
   long apply(long value, T t) throws E;
 
   /**
-   * Returns this functions as an unchecked functions.
+   * Returns given function as an unchecked function.
    *
+   * @param origin the origin function
+   * @param <T>    the type of the second input argument
    * @return unchecked function
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThLongObjToLongFunction<T, RuntimeException> asUnchecked() {
-    return (ThLongObjToLongFunction<T, RuntimeException>) this;
+  static <T> ThLongObjToLongFunction<T, RuntimeException> unchecked(final ThLongObjToLongFunction<? super T, ?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/ThLongSupplier.java b/src/main/java/com/plugatar/jkscope/function/ThLongSupplier.java
index 083a596..ce7b402 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThLongSupplier.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThLongSupplier.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link java.util.function.Supplier} specialization that produces an {@code long}-valued result and might throw an
  * exception.
@@ -34,12 +37,14 @@ public interface ThLongSupplier<E extends Throwable> {
   long get() throws E;
 
   /**
-   * Returns this supplier as an unchecked supplier.
+   * Returns given supplier as an unchecked supplier.
    *
-   * @return unchecked runnable
+   * @param origin the origin supplier
+   * @return unchecked supplier
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThLongSupplier<RuntimeException> asUnchecked() {
-    return (ThLongSupplier<RuntimeException>) this;
+  static ThLongSupplier<RuntimeException> unchecked(final ThLongSupplier<?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/ThLongToLongFunction.java b/src/main/java/com/plugatar/jkscope/function/ThLongToLongFunction.java
index e716366..b20284a 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThLongToLongFunction.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThLongToLongFunction.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link java.util.function.Function} specialization that accepts an {@code long}-valued argument and produces an
  * {@code long}-valued result and might throw an exception.
@@ -35,12 +38,14 @@ public interface ThLongToLongFunction<E extends Throwable> {
   long apply(long value) throws E;
 
   /**
-   * Returns this functions as an unchecked functions.
+   * Returns given function as an unchecked function.
    *
+   * @param origin the origin function
    * @return unchecked function
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThLongToLongFunction<RuntimeException> asUnchecked() {
-    return (ThLongToLongFunction<RuntimeException>) this;
+  static ThLongToLongFunction<RuntimeException> unchecked(final ThLongToLongFunction<?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/ThPredicate.java b/src/main/java/com/plugatar/jkscope/function/ThPredicate.java
index a926cee..26a01d8 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThPredicate.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThPredicate.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link java.util.function.Predicate} specialization that might throw an exception.
  *
@@ -35,12 +38,15 @@ public interface ThPredicate<T, E extends Throwable> {
   boolean test(T t) throws E;
 
   /**
-   * Returns this predicate as an unchecked predicate.
+   * Returns given supplier as an unchecked supplier.
    *
-   * @return unchecked predicate
+   * @param origin the origin supplier
+   * @param <T>    the type of the input argument
+   * @return unchecked supplier
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThPredicate<T, RuntimeException> asUnchecked() {
-    return (ThPredicate<T, RuntimeException>) this;
+  static <T> ThPredicate<T, RuntimeException> unchecked(final ThPredicate<? super T, ?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/ThRunnable.java b/src/main/java/com/plugatar/jkscope/function/ThRunnable.java
index c9e50b8..7ce8aa0 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThRunnable.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThRunnable.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link Runnable} specialization that might throw an exception.
  *
@@ -32,12 +35,14 @@ public interface ThRunnable<E extends Throwable> {
   void run() throws E;
 
   /**
-   * Returns this runnable as an unchecked runnable.
+   * Returns given runnable as an unchecked runnable.
    *
+   * @param origin the origin runnable
    * @return unchecked runnable
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThRunnable<RuntimeException> asUnchecked() {
-    return (ThRunnable<RuntimeException>) this;
+  static ThRunnable<RuntimeException> unchecked(final ThRunnable<?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/ThSupplier.java b/src/main/java/com/plugatar/jkscope/function/ThSupplier.java
index d036223..8025d0d 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThSupplier.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThSupplier.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link java.util.function.Supplier} specialization that might throw an exception.
  *
@@ -34,12 +37,15 @@ public interface ThSupplier<R, E extends Throwable> {
   R get() throws E;
 
   /**
-   * Returns this supplier as an unchecked supplier.
+   * Returns given supplier as an unchecked supplier.
    *
-   * @return unchecked runnable
+   * @param origin the origin supplier
+   * @param <R>    the type of the result
+   * @return unchecked supplier
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThSupplier<R, RuntimeException> asUnchecked() {
-    return (ThSupplier<R, RuntimeException>) this;
+  static <R> ThSupplier<R, RuntimeException> unchecked(final ThSupplier<? extends R, ?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/ThToDoubleFunction.java b/src/main/java/com/plugatar/jkscope/function/ThToDoubleFunction.java
index 1bf7b44..fbcf9ca 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThToDoubleFunction.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThToDoubleFunction.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link java.util.function.Function} specialization that produces a {@code double}-valued result and might throw
  * an exception
@@ -36,12 +39,15 @@ public interface ThToDoubleFunction<T, E extends Throwable> {
   double apply(T t) throws E;
 
   /**
-   * Returns this functions as an unchecked functions.
+   * Returns given function as an unchecked function.
    *
+   * @param origin the origin function
+   * @param <T>    the type of the input argument
    * @return unchecked function
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThToDoubleFunction<T, RuntimeException> asUnchecked() {
-    return (ThToDoubleFunction<T, RuntimeException>) this;
+  static <T> ThToDoubleFunction<T, RuntimeException> unchecked(final ThToDoubleFunction<? super T, ?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/ThToIntFunction.java b/src/main/java/com/plugatar/jkscope/function/ThToIntFunction.java
index 772eca8..120cc70 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThToIntFunction.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThToIntFunction.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link java.util.function.Function} specialization that produces an {@code int}-valued result and might throw an
  * exception
@@ -36,12 +39,15 @@ public interface ThToIntFunction<T, E extends Throwable> {
   int apply(T t) throws E;
 
   /**
-   * Returns this functions as an unchecked functions.
+   * Returns given function as an unchecked function.
    *
+   * @param origin the origin function
+   * @param <T>    the type of the input argument
    * @return unchecked function
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThToIntFunction<T, RuntimeException> asUnchecked() {
-    return (ThToIntFunction<T, RuntimeException>) this;
+  static <T> ThToIntFunction<T, RuntimeException> unchecked(final ThToIntFunction<? super T, ?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/ThToLongFunction.java b/src/main/java/com/plugatar/jkscope/function/ThToLongFunction.java
index 65e1c01..22bc10b 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThToLongFunction.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThToLongFunction.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link java.util.function.Function} specialization that produces a {@code long}-valued result and might throw an
  * exception
@@ -36,12 +39,15 @@ public interface ThToLongFunction<T, E extends Throwable> {
   long apply(T t) throws E;
 
   /**
-   * Returns this functions as an unchecked functions.
+   * Returns given function as an unchecked function.
    *
+   * @param origin the origin function
+   * @param <T>    the type of the input argument
    * @return unchecked function
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThToLongFunction<T, RuntimeException> asUnchecked() {
-    return (ThToLongFunction<T, RuntimeException>) this;
+  static <T> ThToLongFunction<T, RuntimeException> unchecked(final ThToLongFunction<? super T, ?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/ThTriConsumer.java b/src/main/java/com/plugatar/jkscope/function/ThTriConsumer.java
index 1e6728a..795f87b 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThTriConsumer.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThTriConsumer.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link java.util.function.Consumer} specialization for 3 input arguments that might throw an exception.
  *
@@ -37,12 +40,17 @@ public interface ThTriConsumer<T, U, V, E extends Throwable> {
   void accept(T t, U u, V v) throws E;
 
   /**
-   * Returns this consumer as an unchecked consumer.
+   * Returns given consumer as an unchecked consumer.
    *
+   * @param origin the origin consumer
+   * @param <T>    the type of the first input argument
+   * @param <U>    the type of the second input argument
+   * @param <V>    the type of the third input argument
    * @return unchecked consumer
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThTriConsumer<T, U, V, RuntimeException> asUnchecked() {
-    return (ThTriConsumer<T, U, V, RuntimeException>) this;
+  static <T, U, V> ThTriConsumer<T, U, V, RuntimeException> unchecked(final ThTriConsumer<? super T, ? super U, ? super V, ?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/ThTriFunction.java b/src/main/java/com/plugatar/jkscope/function/ThTriFunction.java
index 8b60579..c58d092 100644
--- a/src/main/java/com/plugatar/jkscope/function/ThTriFunction.java
+++ b/src/main/java/com/plugatar/jkscope/function/ThTriFunction.java
@@ -15,6 +15,9 @@
  */
 package com.plugatar.jkscope.function;
 
+import static com.plugatar.jkscope.function.Utils.originArgNotNull;
+import static com.plugatar.jkscope.function.Utils.uncheckedCast;
+
 /**
  * The {@link java.util.function.Function} specialization for 3 input arguments that might throw an exception.
  *
@@ -39,12 +42,18 @@ public interface ThTriFunction<T, U, V, R, E extends Throwable> {
   R apply(T t, U u, V v) throws E;
 
   /**
-   * Returns this functions as an unchecked functions.
+   * Returns given function as an unchecked function.
    *
+   * @param origin the origin function
+   * @param <T>    the type of the first input argument
+   * @param <U>    the type of the second input argument
+   * @param <V>    the type of the third input argument
+   * @param <R>    the type of the result
    * @return unchecked function
+   * @throws NullPointerException if {@code origin} arg is null
    */
-  @SuppressWarnings("unchecked")
-  default ThTriFunction<T, U, V, R, RuntimeException> asUnchecked() {
-    return (ThTriFunction<T, U, V, R, RuntimeException>) this;
+  static <T, U, V, R> ThTriFunction<T, U, V, R, RuntimeException> unchecked(final ThTriFunction<? super T, ? super U, ? super V, ? extends R, ?> origin) {
+    originArgNotNull(origin);
+    return uncheckedCast(origin);
   }
 }
diff --git a/src/main/java/com/plugatar/jkscope/function/Utils.java b/src/main/java/com/plugatar/jkscope/function/Utils.java
new file mode 100644
index 0000000..0177259
--- /dev/null
+++ b/src/main/java/com/plugatar/jkscope/function/Utils.java
@@ -0,0 +1,24 @@
+package com.plugatar.jkscope.function;
+
+/**
+ * Utility methods.
+ */
+final class Utils {
+
+  /**
+   * Ctor.
+   */
+  private Utils() {
+  }
+
+  static void originArgNotNull(final Object origin) {
+    if (origin == null) {
+      throw new NullPointerException("origin arg is null");
+    }
+  }
+
+  @SuppressWarnings("unchecked")
+  static <T> T uncheckedCast(final Object obj) {
+    return (T) obj;
+  }
+}
diff --git a/src/test/java/com/plugatar/jkscope/function/ThBiConsumerTest.java b/src/test/java/com/plugatar/jkscope/function/ThBiConsumerTest.java
index b4a1cca..8bbeef3 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThBiConsumerTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThBiConsumerTest.java
@@ -28,7 +28,15 @@
 final class ThBiConsumerTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThBiConsumer<Object, Object, Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThBiConsumer.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final Object value1 = new Object();
     final Object value2 = new Object();
     final AtomicReference<Object> valueRef1 = new AtomicReference<>();
@@ -40,7 +48,7 @@ void asUncheckedMethod() {
       throw throwable;
     };
 
-    final ThBiConsumer<Object, Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThBiConsumer<Object, Object, RuntimeException> unchecked = ThBiConsumer.unchecked(origin);
     assertThatThrownBy(() -> unchecked.accept(value1, value2))
       .isSameAs(throwable);
     assertThat(valueRef1.get())
diff --git a/src/test/java/com/plugatar/jkscope/function/ThBiFunctionTest.java b/src/test/java/com/plugatar/jkscope/function/ThBiFunctionTest.java
index 2710c51..e2d9bfe 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThBiFunctionTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThBiFunctionTest.java
@@ -28,7 +28,15 @@
 final class ThBiFunctionTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThBiFunction<Object, Object, Object, Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThBiFunction.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final Object value1 = new Object();
     final Object value2 = new Object();
     final AtomicReference<Object> valueRef1 = new AtomicReference<>();
@@ -40,7 +48,7 @@ void asUncheckedMethod() {
       return result;
     };
 
-    final ThBiFunction<Object, Object, Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThBiFunction<Object, Object, Object, RuntimeException> unchecked = ThBiFunction.unchecked(origin);
     assertThat(unchecked.apply(value1, value2))
       .isSameAs(result);
     assertThat(valueRef1.get())
@@ -50,13 +58,13 @@ void asUncheckedMethod() {
   }
 
   @Test
-  void asUncheckedMethodThrowsException() {
+  void uncheckedStaticMethodThrowsException() {
     final Object value1 = new Object();
     final Object value2 = new Object();
     final Throwable throwable = new Throwable();
     final ThBiFunction<Object, Object, Object, Throwable> origin = (arg1, arg2) -> { throw throwable; };
 
-    final ThBiFunction<Object, Object, Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThBiFunction<Object, Object, Object, RuntimeException> unchecked = ThBiFunction.unchecked(origin);
     assertThatThrownBy(() -> unchecked.apply(value1, value2))
       .isSameAs(throwable);
   }
diff --git a/src/test/java/com/plugatar/jkscope/function/ThConsumerTest.java b/src/test/java/com/plugatar/jkscope/function/ThConsumerTest.java
index 5153cc9..c82cbe8 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThConsumerTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThConsumerTest.java
@@ -28,7 +28,15 @@
 final class ThConsumerTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThConsumer<Object, Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThConsumer.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final Object value = new Object();
     final AtomicReference<Object> valueRef = new AtomicReference<>();
     final Throwable throwable = new Throwable();
@@ -37,7 +45,7 @@ void asUncheckedMethod() {
       throw throwable;
     };
 
-    final ThConsumer<Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThConsumer<Object, RuntimeException> unchecked = ThConsumer.unchecked(origin);
     assertThatThrownBy(() -> unchecked.accept(value))
       .isSameAs(throwable);
     assertThat(valueRef.get())
diff --git a/src/test/java/com/plugatar/jkscope/function/ThDoubleConsumerTest.java b/src/test/java/com/plugatar/jkscope/function/ThDoubleConsumerTest.java
index 70d9b1a..43c8840 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThDoubleConsumerTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThDoubleConsumerTest.java
@@ -28,7 +28,15 @@
 final class ThDoubleConsumerTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThDoubleConsumer<Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThDoubleConsumer.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final double value = 100.0;
     final AtomicReference<Double> valueRef = new AtomicReference<>();
     final Throwable throwable = new Throwable();
@@ -37,7 +45,7 @@ void asUncheckedMethod() {
       throw throwable;
     };
 
-    final ThDoubleConsumer<RuntimeException> unchecked = origin.asUnchecked();
+    final ThDoubleConsumer<RuntimeException> unchecked = ThDoubleConsumer.unchecked(origin);
     assertThatThrownBy(() -> unchecked.accept(value))
       .isSameAs(throwable);
     assertThat(valueRef.get())
diff --git a/src/test/java/com/plugatar/jkscope/function/ThDoubleObjToDoubleFunctionTest.java b/src/test/java/com/plugatar/jkscope/function/ThDoubleObjToDoubleFunctionTest.java
index a5307e8..7ba48f7 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThDoubleObjToDoubleFunctionTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThDoubleObjToDoubleFunctionTest.java
@@ -28,7 +28,15 @@
 final class ThDoubleObjToDoubleFunctionTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThDoubleObjToDoubleFunction<Object, Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThDoubleObjToDoubleFunction.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final double value1 = 100.0;
     final Object value2 = new Object();
     final AtomicReference<Double> value1Ref = new AtomicReference();
@@ -40,7 +48,7 @@ void asUncheckedMethod() {
       return result;
     };
 
-    final ThDoubleObjToDoubleFunction<Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThDoubleObjToDoubleFunction<Object, RuntimeException> unchecked = ThDoubleObjToDoubleFunction.unchecked(origin);
     assertThat(unchecked.apply(value1, value2))
       .isEqualTo(result);
     assertThat(value1Ref.get())
@@ -50,13 +58,13 @@ void asUncheckedMethod() {
   }
 
   @Test
-  void asUncheckedMethodThrowsException() {
+  void uncheckedStaticMethodThrowsException() {
     final double value1 = 100.0;
     final Object value2 = new Object();
     final Throwable throwable = new Throwable();
     final ThDoubleObjToDoubleFunction<Object, Throwable> origin = (arg1, arg2) -> { throw throwable; };
 
-    final ThDoubleObjToDoubleFunction<Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThDoubleObjToDoubleFunction<Object, RuntimeException> unchecked = ThDoubleObjToDoubleFunction.unchecked(origin);
     assertThatThrownBy(() -> unchecked.apply(value1, value2))
       .isSameAs(throwable);
   }
diff --git a/src/test/java/com/plugatar/jkscope/function/ThDoubleSupplierTest.java b/src/test/java/com/plugatar/jkscope/function/ThDoubleSupplierTest.java
index c83dc4d..7a2d40d 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThDoubleSupplierTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThDoubleSupplierTest.java
@@ -26,21 +26,29 @@
 final class ThDoubleSupplierTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThDoubleSupplier<Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThDoubleSupplier.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final double result = 100.0;
     final ThDoubleSupplier<Throwable> origin = () -> result;
 
-    final ThDoubleSupplier<RuntimeException> unchecked = origin.asUnchecked();
+    final ThDoubleSupplier<RuntimeException> unchecked = ThDoubleSupplier.unchecked(origin);
     assertThat(unchecked.get())
       .isEqualTo(result);
   }
 
   @Test
-  void asUncheckedMethodThrowsException() {
+  void uncheckedStaticMethodThrowsException() {
     final Throwable throwable = new Throwable();
     final ThDoubleSupplier<Throwable> origin = () -> { throw throwable; };
 
-    final ThDoubleSupplier<RuntimeException> unchecked = origin.asUnchecked();
+    final ThDoubleSupplier<RuntimeException> unchecked = ThDoubleSupplier.unchecked(origin);
     assertThatThrownBy(() -> unchecked.get())
       .isSameAs(throwable);
   }
diff --git a/src/test/java/com/plugatar/jkscope/function/ThDoubleToDoubleFunctionTest.java b/src/test/java/com/plugatar/jkscope/function/ThDoubleToDoubleFunctionTest.java
index 7d55ecc..2726f39 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThDoubleToDoubleFunctionTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThDoubleToDoubleFunctionTest.java
@@ -28,7 +28,15 @@
 final class ThDoubleToDoubleFunctionTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThDoubleToDoubleFunction<Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThDoubleToDoubleFunction.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final double value = 100.0;
     final AtomicReference<Double> valueRef = new AtomicReference<>();
     final double result = 999.0;
@@ -37,7 +45,7 @@ void asUncheckedMethod() {
       return result;
     };
 
-    final ThDoubleToDoubleFunction<RuntimeException> unchecked = origin.asUnchecked();
+    final ThDoubleToDoubleFunction<RuntimeException> unchecked = ThDoubleToDoubleFunction.unchecked(origin);
     assertThat(unchecked.apply(value))
       .isEqualTo(result);
     assertThat(valueRef.get())
@@ -45,12 +53,12 @@ void asUncheckedMethod() {
   }
 
   @Test
-  void asUncheckedMethodThrowsException() {
+  void uncheckedStaticMethodThrowsException() {
     final double value = 100.0;
     final Throwable throwable = new Throwable();
     final ThDoubleToDoubleFunction<Throwable> origin = arg -> { throw throwable; };
 
-    final ThDoubleToDoubleFunction<RuntimeException> unchecked = origin.asUnchecked();
+    final ThDoubleToDoubleFunction<RuntimeException> unchecked = ThDoubleToDoubleFunction.unchecked(origin);
     assertThatThrownBy(() -> unchecked.apply(value))
       .isSameAs(throwable);
   }
diff --git a/src/test/java/com/plugatar/jkscope/function/ThFunctionTest.java b/src/test/java/com/plugatar/jkscope/function/ThFunctionTest.java
index 10c3c0c..e0c3d59 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThFunctionTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThFunctionTest.java
@@ -28,7 +28,15 @@
 final class ThFunctionTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThFunction<Object, Object, Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThFunction.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final Object value = new Object();
     final AtomicReference<Object> valueRef = new AtomicReference<>();
     final Object result = new Object();
@@ -37,7 +45,7 @@ void asUncheckedMethod() {
       return result;
     };
 
-    final ThFunction<Object, Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThFunction<Object, Object, RuntimeException> unchecked = ThFunction.unchecked(origin);
     assertThat(unchecked.apply(value))
       .isSameAs(result);
     assertThat(valueRef.get())
@@ -45,12 +53,12 @@ void asUncheckedMethod() {
   }
 
   @Test
-  void asUncheckedMethodThrowsException() {
+  void uncheckedStaticMethodThrowsException() {
     final Object value = new Object();
     final Throwable throwable = new Throwable();
     final ThFunction<Object, Object, Throwable> origin = arg -> { throw throwable; };
 
-    final ThFunction<Object, Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThFunction<Object, Object, RuntimeException> unchecked = ThFunction.unchecked(origin);
     assertThatThrownBy(() -> unchecked.apply(value))
       .isSameAs(throwable);
   }
diff --git a/src/test/java/com/plugatar/jkscope/function/ThIntConsumerTest.java b/src/test/java/com/plugatar/jkscope/function/ThIntConsumerTest.java
index 74f0192..2c2e133 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThIntConsumerTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThIntConsumerTest.java
@@ -28,7 +28,15 @@
 final class ThIntConsumerTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThIntConsumer<Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThIntConsumer.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final int value = 100;
     final AtomicInteger valueRef = new AtomicInteger();
     final Throwable throwable = new Throwable();
@@ -37,7 +45,7 @@ void asUncheckedMethod() {
       throw throwable;
     };
 
-    final ThIntConsumer<RuntimeException> unchecked = origin.asUnchecked();
+    final ThIntConsumer<RuntimeException> unchecked = ThIntConsumer.unchecked(origin);
     assertThatThrownBy(() -> unchecked.accept(value))
       .isSameAs(throwable);
     assertThat(valueRef.get())
diff --git a/src/test/java/com/plugatar/jkscope/function/ThIntObjToIntFunctionTest.java b/src/test/java/com/plugatar/jkscope/function/ThIntObjToIntFunctionTest.java
index cec21fa..31b00fb 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThIntObjToIntFunctionTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThIntObjToIntFunctionTest.java
@@ -29,7 +29,15 @@
 final class ThIntObjToIntFunctionTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThIntObjToIntFunction<Object, Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThIntObjToIntFunction.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final int value1 = 100;
     final Object value2 = new Object();
     final AtomicInteger value1Ref = new AtomicInteger();
@@ -41,7 +49,7 @@ void asUncheckedMethod() {
       return result;
     };
 
-    final ThIntObjToIntFunction<Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThIntObjToIntFunction<Object, RuntimeException> unchecked = ThIntObjToIntFunction.unchecked(origin);
     assertThat(unchecked.apply(value1, value2))
       .isEqualTo(result);
     assertThat(value1Ref.get())
@@ -51,13 +59,13 @@ void asUncheckedMethod() {
   }
 
   @Test
-  void asUncheckedMethodThrowsException() {
+  void uncheckedStaticMethodThrowsException() {
     final int value1 = 100;
     final Object value2 = new Object();
     final Throwable throwable = new Throwable();
     final ThIntObjToIntFunction<Object, Throwable> origin = (arg1, arg2) -> { throw throwable; };
 
-    final ThIntObjToIntFunction<Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThIntObjToIntFunction<Object, RuntimeException> unchecked = ThIntObjToIntFunction.unchecked(origin);
     assertThatThrownBy(() -> unchecked.apply(value1, value2))
       .isSameAs(throwable);
   }
diff --git a/src/test/java/com/plugatar/jkscope/function/ThIntSupplierTest.java b/src/test/java/com/plugatar/jkscope/function/ThIntSupplierTest.java
index 677528e..954ab73 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThIntSupplierTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThIntSupplierTest.java
@@ -26,21 +26,29 @@
 final class ThIntSupplierTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThIntSupplier<Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThIntSupplier.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final int result = 100;
     final ThIntSupplier<Throwable> origin = () -> result;
 
-    final ThIntSupplier<RuntimeException> unchecked = origin.asUnchecked();
+    final ThIntSupplier<RuntimeException> unchecked = ThIntSupplier.unchecked(origin);
     assertThat(unchecked.get())
       .isEqualTo(result);
   }
 
   @Test
-  void asUncheckedMethodThrowsException() {
+  void uncheckedStaticMethodThrowsException() {
     final Throwable throwable = new Throwable();
     final ThIntSupplier<Throwable> origin = () -> { throw throwable; };
 
-    final ThIntSupplier<RuntimeException> unchecked = origin.asUnchecked();
+    final ThIntSupplier<RuntimeException> unchecked = ThIntSupplier.unchecked(origin);
     assertThatThrownBy(() -> unchecked.get())
       .isSameAs(throwable);
   }
diff --git a/src/test/java/com/plugatar/jkscope/function/ThIntToIntFunctionTest.java b/src/test/java/com/plugatar/jkscope/function/ThIntToIntFunctionTest.java
index a764966..53a305f 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThIntToIntFunctionTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThIntToIntFunctionTest.java
@@ -28,7 +28,15 @@
 final class ThIntToIntFunctionTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThIntToIntFunction<Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThIntToIntFunction.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final int value = 100;
     final AtomicInteger valueRef = new AtomicInteger();
     final int result = 999;
@@ -37,7 +45,7 @@ void asUncheckedMethod() {
       return result;
     };
 
-    final ThIntToIntFunction<RuntimeException> unchecked = origin.asUnchecked();
+    final ThIntToIntFunction<RuntimeException> unchecked = ThIntToIntFunction.unchecked(origin);
     assertThat(unchecked.apply(value))
       .isEqualTo(result);
     assertThat(valueRef.get())
@@ -45,12 +53,12 @@ void asUncheckedMethod() {
   }
 
   @Test
-  void asUncheckedMethodThrowsException() {
+  void uncheckedStaticMethodThrowsException() {
     final int value = 100;
     final Throwable throwable = new Throwable();
     final ThIntToIntFunction<Throwable> origin = arg -> { throw throwable; };
 
-    final ThIntToIntFunction<RuntimeException> unchecked = origin.asUnchecked();
+    final ThIntToIntFunction<RuntimeException> unchecked = ThIntToIntFunction.unchecked(origin);
     assertThatThrownBy(() -> unchecked.apply(value))
       .isSameAs(throwable);
   }
diff --git a/src/test/java/com/plugatar/jkscope/function/ThLongConsumerTest.java b/src/test/java/com/plugatar/jkscope/function/ThLongConsumerTest.java
index 17e99e7..c3b76ca 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThLongConsumerTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThLongConsumerTest.java
@@ -28,7 +28,15 @@
 final class ThLongConsumerTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThLongConsumer<Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThLongConsumer.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final long value = 100L;
     final AtomicLong valueRef = new AtomicLong();
     final Throwable throwable = new Throwable();
@@ -37,7 +45,7 @@ void asUncheckedMethod() {
       throw throwable;
     };
 
-    final ThLongConsumer<RuntimeException> unchecked = origin.asUnchecked();
+    final ThLongConsumer<RuntimeException> unchecked = ThLongConsumer.unchecked(origin);
     assertThatThrownBy(() -> unchecked.accept(value))
       .isSameAs(throwable);
     assertThat(valueRef.get())
diff --git a/src/test/java/com/plugatar/jkscope/function/ThLongObjToLongFunctionTest.java b/src/test/java/com/plugatar/jkscope/function/ThLongObjToLongFunctionTest.java
index 8ffafb7..91bd9fd 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThLongObjToLongFunctionTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThLongObjToLongFunctionTest.java
@@ -29,7 +29,15 @@
 final class ThLongObjToLongFunctionTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThLongObjToLongFunction<Object, Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThLongObjToLongFunction.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final long value1 = 100L;
     final Object value2 = new Object();
     final AtomicLong value1Ref = new AtomicLong();
@@ -41,7 +49,7 @@ void asUncheckedMethod() {
       return result;
     };
 
-    final ThLongObjToLongFunction<Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThLongObjToLongFunction<Object, RuntimeException> unchecked = ThLongObjToLongFunction.unchecked(origin);
     assertThat(unchecked.apply(value1, value2))
       .isEqualTo(result);
     assertThat(value1Ref.get())
@@ -51,13 +59,13 @@ void asUncheckedMethod() {
   }
 
   @Test
-  void asUncheckedMethodThrowsException() {
+  void uncheckedStaticMethodThrowsException() {
     final long value1 = 100L;
     final Object value2 = new Object();
     final Throwable throwable = new Throwable();
     final ThLongObjToLongFunction<Object, Throwable> origin = (arg1, arg2) -> { throw throwable; };
 
-    final ThLongObjToLongFunction<Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThLongObjToLongFunction<Object, RuntimeException> unchecked = ThLongObjToLongFunction.unchecked(origin);
     assertThatThrownBy(() -> unchecked.apply(value1, value2))
       .isSameAs(throwable);
   }
diff --git a/src/test/java/com/plugatar/jkscope/function/ThLongSupplierTest.java b/src/test/java/com/plugatar/jkscope/function/ThLongSupplierTest.java
index 2e6a1ae..6292a8d 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThLongSupplierTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThLongSupplierTest.java
@@ -26,21 +26,29 @@
 final class ThLongSupplierTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThLongSupplier<Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThLongSupplier.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final long result = 100L;
     final ThLongSupplier<Throwable> origin = () -> result;
 
-    final ThLongSupplier<RuntimeException> unchecked = origin.asUnchecked();
+    final ThLongSupplier<RuntimeException> unchecked = ThLongSupplier.unchecked(origin);
     assertThat(unchecked.get())
       .isEqualTo(result);
   }
 
   @Test
-  void asUncheckedMethodThrowsException() {
+  void uncheckedStaticMethodThrowsException() {
     final Throwable throwable = new Throwable();
     final ThLongSupplier<Throwable> origin = () -> { throw throwable; };
 
-    final ThLongSupplier<RuntimeException> unchecked = origin.asUnchecked();
+    final ThLongSupplier<RuntimeException> unchecked = ThLongSupplier.unchecked(origin);
     assertThatThrownBy(() -> unchecked.get())
       .isSameAs(throwable);
   }
diff --git a/src/test/java/com/plugatar/jkscope/function/ThLongToLongFunctionTest.java b/src/test/java/com/plugatar/jkscope/function/ThLongToLongFunctionTest.java
index 46d0c09..21907f0 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThLongToLongFunctionTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThLongToLongFunctionTest.java
@@ -28,7 +28,15 @@
 final class ThLongToLongFunctionTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThLongToLongFunction<Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThLongToLongFunction.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final long value = 100;
     final AtomicLong valueRef = new AtomicLong();
     final long result = 999;
@@ -37,7 +45,7 @@ void asUncheckedMethod() {
       return result;
     };
 
-    final ThLongToLongFunction<RuntimeException> unchecked = origin.asUnchecked();
+    final ThLongToLongFunction<RuntimeException> unchecked = ThLongToLongFunction.unchecked(origin);
     assertThat(unchecked.apply(value))
       .isEqualTo(result);
     assertThat(valueRef.get())
@@ -45,12 +53,12 @@ void asUncheckedMethod() {
   }
 
   @Test
-  void asUncheckedMethodThrowsException() {
+  void uncheckedStaticMethodThrowsException() {
     final long value = 100;
     final Throwable throwable = new Throwable();
     final ThLongToLongFunction<Throwable> origin = arg -> { throw throwable; };
 
-    final ThLongToLongFunction<RuntimeException> unchecked = origin.asUnchecked();
+    final ThLongToLongFunction<RuntimeException> unchecked = ThLongToLongFunction.unchecked(origin);
     assertThatThrownBy(() -> unchecked.apply(value))
       .isSameAs(throwable);
   }
diff --git a/src/test/java/com/plugatar/jkscope/function/ThPredicateTest.java b/src/test/java/com/plugatar/jkscope/function/ThPredicateTest.java
index 4b45d86..7300547 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThPredicateTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThPredicateTest.java
@@ -28,7 +28,15 @@
 final class ThPredicateTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThPredicate<Object, Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThPredicate.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final Object value = new Object();
     final AtomicReference<Object> valueRef = new AtomicReference<>();
     final boolean result = true;
@@ -37,7 +45,7 @@ void asUncheckedMethod() {
       return result;
     };
 
-    final ThPredicate<Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThPredicate<Object, RuntimeException> unchecked = ThPredicate.unchecked(origin);
     assertThat(unchecked.test(value))
       .isSameAs(result);
     assertThat(valueRef.get())
@@ -45,12 +53,12 @@ void asUncheckedMethod() {
   }
 
   @Test
-  void asUncheckedMethodThrowsException() {
+  void uncheckedStaticMethodThrowsException() {
     final Object value = new Object();
     final Throwable throwable = new Throwable();
     final ThPredicate<Object, Throwable> origin = arg -> { throw throwable; };
 
-    final ThPredicate<Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThPredicate<Object, RuntimeException> unchecked = ThPredicate.unchecked(origin);
     assertThatThrownBy(() -> unchecked.test(value))
       .isSameAs(throwable);
   }
diff --git a/src/test/java/com/plugatar/jkscope/function/ThRunnableTest.java b/src/test/java/com/plugatar/jkscope/function/ThRunnableTest.java
index 075d43b..20f3752 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThRunnableTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThRunnableTest.java
@@ -28,7 +28,15 @@
 final class ThRunnableTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThRunnable<Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThRunnable.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final AtomicBoolean sideEffect = new AtomicBoolean(false);
     final Throwable throwable = new Throwable();
     final ThRunnable<Throwable> origin = () -> {
@@ -36,7 +44,7 @@ void asUncheckedMethod() {
       throw throwable;
     };
 
-    final ThRunnable<RuntimeException> unchecked = origin.asUnchecked();
+    final ThRunnable<RuntimeException> unchecked = ThRunnable.unchecked(origin);
     assertThatThrownBy(() -> unchecked.run())
       .isSameAs(throwable);
     assertThat(sideEffect.get())
diff --git a/src/test/java/com/plugatar/jkscope/function/ThSupplierTest.java b/src/test/java/com/plugatar/jkscope/function/ThSupplierTest.java
index 7f5c953..cfd141f 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThSupplierTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThSupplierTest.java
@@ -26,21 +26,29 @@
 final class ThSupplierTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThSupplier<Object, Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThSupplier.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final Object result = new Object();
     final ThSupplier<Object, Throwable> origin = () -> result;
 
-    final ThSupplier<Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThSupplier<Object, RuntimeException> unchecked = ThSupplier.unchecked(origin);
     assertThat(unchecked.get())
       .isSameAs(result);
   }
 
   @Test
-  void asUncheckedMethodThrowsException() {
+  void uncheckedStaticMethodThrowsException() {
     final Throwable throwable = new Throwable();
     final ThSupplier<Object, Throwable> origin = () -> { throw throwable; };
 
-    final ThSupplier<Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThSupplier<Object, RuntimeException> unchecked = ThSupplier.unchecked(origin);
     assertThatThrownBy(() -> unchecked.get())
       .isSameAs(throwable);
   }
diff --git a/src/test/java/com/plugatar/jkscope/function/ThToDoubleFunctionTest.java b/src/test/java/com/plugatar/jkscope/function/ThToDoubleFunctionTest.java
index 8681fda..d5e8800 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThToDoubleFunctionTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThToDoubleFunctionTest.java
@@ -28,7 +28,15 @@
 final class ThToDoubleFunctionTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThToDoubleFunction<Object, Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThToDoubleFunction.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final Object value = new Object();
     final AtomicReference<Object> valueRef = new AtomicReference<>();
     final double result = 111.0;
@@ -37,7 +45,7 @@ void asUncheckedMethod() {
       return result;
     };
 
-    final ThToDoubleFunction<Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThToDoubleFunction<Object, RuntimeException> unchecked = ThToDoubleFunction.unchecked(origin);
     assertThat(unchecked.apply(value))
       .isEqualTo(result);
     assertThat(valueRef.get())
@@ -45,12 +53,12 @@ void asUncheckedMethod() {
   }
 
   @Test
-  void asUncheckedMethodThrowsException() {
+  void uncheckedStaticMethodThrowsException() {
     final Object value = new Object();
     final Throwable throwable = new Throwable();
     final ThToDoubleFunction<Object, Throwable> origin = arg -> { throw throwable; };
 
-    final ThToDoubleFunction<Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThToDoubleFunction<Object, RuntimeException> unchecked = ThToDoubleFunction.unchecked(origin);
     assertThatThrownBy(() -> unchecked.apply(value))
       .isSameAs(throwable);
   }
diff --git a/src/test/java/com/plugatar/jkscope/function/ThToIntFunctionTest.java b/src/test/java/com/plugatar/jkscope/function/ThToIntFunctionTest.java
index 03566a9..2f25c45 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThToIntFunctionTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThToIntFunctionTest.java
@@ -28,7 +28,15 @@
 final class ThToIntFunctionTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThToIntFunction<Object, Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThToIntFunction.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final Object value = new Object();
     final AtomicReference<Object> valueRef = new AtomicReference<>();
     final int result = 111;
@@ -37,7 +45,7 @@ void asUncheckedMethod() {
       return result;
     };
 
-    final ThToIntFunction<Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThToIntFunction<Object, RuntimeException> unchecked = ThToIntFunction.unchecked(origin);
     assertThat(unchecked.apply(value))
       .isEqualTo(result);
     assertThat(valueRef.get())
@@ -45,12 +53,12 @@ void asUncheckedMethod() {
   }
 
   @Test
-  void asUncheckedMethodThrowsException() {
+  void uncheckedStaticMethodThrowsException() {
     final Object value = new Object();
     final Throwable throwable = new Throwable();
     final ThToIntFunction<Object, Throwable> origin = arg -> { throw throwable; };
 
-    final ThToIntFunction<Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThToIntFunction<Object, RuntimeException> unchecked = ThToIntFunction.unchecked(origin);
     assertThatThrownBy(() -> unchecked.apply(value))
       .isSameAs(throwable);
   }
diff --git a/src/test/java/com/plugatar/jkscope/function/ThToLongFunctionTest.java b/src/test/java/com/plugatar/jkscope/function/ThToLongFunctionTest.java
index 2eb6770..66e02c9 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThToLongFunctionTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThToLongFunctionTest.java
@@ -28,7 +28,15 @@
 final class ThToLongFunctionTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThToLongFunction<Object, Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThToLongFunction.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final Object value = new Object();
     final AtomicReference<Object> valueRef = new AtomicReference<>();
     final long result = 111L;
@@ -37,7 +45,7 @@ void asUncheckedMethod() {
       return result;
     };
 
-    final ThToLongFunction<Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThToLongFunction<Object, RuntimeException> unchecked = ThToLongFunction.unchecked(origin);
     assertThat(unchecked.apply(value))
       .isEqualTo(result);
     assertThat(valueRef.get())
@@ -45,12 +53,12 @@ void asUncheckedMethod() {
   }
 
   @Test
-  void asUncheckedMethodThrowsException() {
+  void uncheckedStaticMethodThrowsException() {
     final Object value = new Object();
     final Throwable throwable = new Throwable();
     final ThToLongFunction<Object, Throwable> origin = arg -> { throw throwable; };
 
-    final ThToLongFunction<Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThToLongFunction<Object, RuntimeException> unchecked = ThToLongFunction.unchecked(origin);
     assertThatThrownBy(() -> unchecked.apply(value))
       .isSameAs(throwable);
   }
diff --git a/src/test/java/com/plugatar/jkscope/function/ThTriConsumerTest.java b/src/test/java/com/plugatar/jkscope/function/ThTriConsumerTest.java
index 52f5ba3..f4e53ca 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThTriConsumerTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThTriConsumerTest.java
@@ -28,7 +28,15 @@
 final class ThTriConsumerTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThTriConsumer<Object, Object, Object, Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThTriConsumer.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final Object value1 = new Object();
     final Object value2 = new Object();
     final Object value3 = new Object();
@@ -43,7 +51,7 @@ void asUncheckedMethod() {
       throw throwable;
     };
 
-    final ThTriConsumer<Object, Object, Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThTriConsumer<Object, Object, Object, RuntimeException> unchecked = ThTriConsumer.unchecked(origin);
     assertThatThrownBy(() -> unchecked.accept(value1, value2, value3))
       .isSameAs(throwable);
     assertThat(valueRef1.get())
diff --git a/src/test/java/com/plugatar/jkscope/function/ThTriFunctionTest.java b/src/test/java/com/plugatar/jkscope/function/ThTriFunctionTest.java
index 24197e2..4ea6eb2 100644
--- a/src/test/java/com/plugatar/jkscope/function/ThTriFunctionTest.java
+++ b/src/test/java/com/plugatar/jkscope/function/ThTriFunctionTest.java
@@ -28,7 +28,15 @@
 final class ThTriFunctionTest {
 
   @Test
-  void asUncheckedMethod() {
+  void uncheckedStaticMethodThrowsNPEForNullArg() {
+    final ThTriFunction<Object, Object, Object, Object, Throwable> origin = null;
+
+    assertThatThrownBy(() -> ThTriFunction.unchecked(origin))
+      .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void uncheckedStaticMethod() {
     final Object value1 = new Object();
     final Object value2 = new Object();
     final Object value3 = new Object();
@@ -43,7 +51,7 @@ void asUncheckedMethod() {
       return functionResult;
     };
 
-    final ThTriFunction<Object, Object, Object, Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThTriFunction<Object, Object, Object, Object, RuntimeException> unchecked = ThTriFunction.unchecked(origin);
     assertThat(unchecked.apply(value1, value2, value3))
       .isSameAs(functionResult);
     assertThat(valueRef1.get())
@@ -55,7 +63,7 @@ void asUncheckedMethod() {
   }
 
   @Test
-  void asUncheckedMethodThrowsException() {
+  void uncheckedStaticMethodThrowsException() {
     final Object value1 = new Object();
     final Object value2 = new Object();
     final Object value3 = new Object();
@@ -64,7 +72,7 @@ void asUncheckedMethodThrowsException() {
       throw throwable;
     };
 
-    final ThTriFunction<Object, Object, Object, Object, RuntimeException> unchecked = origin.asUnchecked();
+    final ThTriFunction<Object, Object, Object, Object, RuntimeException> unchecked = ThTriFunction.unchecked(origin);
     assertThatThrownBy(() -> unchecked.apply(value1, value2, value3))
       .isSameAs(throwable);
   }