Merge pull request #11 from shan-shaji/fix/remove-late-keyword

fix: remove late keyword from chain_of_responsibility

Author: scottt2

chain_of_responsibility/README.md

@@ -26,7 +26,7 @@ enum LogLevel {
 
 abstract class Logger {
   Set<LogLevel> levels;
-  Logger _next;
+  Logger? _next;
 
   Logger(this.levels);
 

chain_of_responsibility/chain_of_responsibility.dart

@@ -9,8 +9,8 @@ enum LogLevel {
 }
 
 abstract class Logger {
-  late Set<LogLevel> levels;
-  late Logger _next;
+  Set<LogLevel> levels;
+  Logger? _next;
 
   Logger(this.levels);
 
@@ -23,7 +23,7 @@ abstract class Logger {
     if (levels.contains(level) || universal) {
       write_message(msg);
     }
-    _next.log(level, msg);
+    _next?.log(level, msg);
   }
 
   void write_message(String msg);