anchor.diff:    covariant num foo;
   }
   class C extends A {
  -  covariant @virtual num foo;
  +  covariant num foo;
   }
   class D extends C {
  -  @virtual int foo;
  +  int foo;
   }
   class E extends D {
  -  @virtual num foo;
  +  num foo;
   }
       ''');
     }
  
positive.code:   final ToVoid<dynamic> g = null;
  }
   ''');
    }
  
    test_fieldOverride_virtual() async {
      _addMetaLibrary();
      await checkFile(r'''
  import 'meta.dart';
  class C {
    @virtual int x;
  }
  class OverrideGetter extends C {
    int get x => 42;
  }
  class OverrideSetter extends C {
    set x(int v) {}
  }
  class OverrideBoth extends C {
    int get x => 42;
    set x(int v) {}
  }
  class OverrideWithField extends C {
    int x;
  
    // expose the hidden storage slot
    int get superX => super.x;
    set superX(int v) { super.x = v; }
  }
  class VirtualNotInherited extends OverrideWithField {
    int x;
  }
      ''');
    }
  
    test_fieldSetterOverride() async {
  
negative.code: }
  ''');
    }
  }
  