anchor.diff:  
   const SOURCE = const {
     'main.dart': '''
  +import 'dart:html';
  +import 'package:expect/expect.dart';
   
   class ClassWithSetter {
     void set setter(_) {}
  
positive.code:   new Class2().method2();
    new Class2().method3();
    new Class2().method5();
  }
  '''
  };
  
negative.code:     super.field = null;
    }
  }
   
  method1() {} // Deliberately the same name as the instance member in Mixin.
  
  @NoInline()
  main() {
    print('Hello World');
    ''.contains; // Trigger member closurization.
  