anchor.diff:      yield* statements;
     }
   
  -  CompoundStatement(this.openingBracket,
  -      {@required List<Label> labels, @required AstNode parent})
  +  CompoundStatement(
  +      {@required this.openingBracket,
  +      @required List<Label> labels,
  +      @required AstNode parent})
         : super(labels, parent);
   }
   
  
positive.code: /// namespace. All top-level functions, typedefs and global variables are added
  /// to this scope.
  ///
  /// The `parent` of a namespace is `null`.
  class Namespace extends AstNode with Scope {
    Namespace() : super(null);
  
  
negative.code:     yield body;
    }
  
    IfStatement(
        {@required this.expression,
        @required this.body,
        @required List<Label> labels,
        @required AstNode parent})
        : super(labels, parent);
  }
  
  