anchor.diff:  
     SendVisitor(this.collector, TreeElements elements) : super(elements);
   
  +  visitDynamicSend(Send node) {}
     visitSuperSend(Send node) {}
     visitOperatorSend(Send node) {}
     visitForeignSend(Send node) {}
  
positive.code:       }
      }
      send.visitChildren(this);
    }
  
    static bool isPlainTypeName(TypeAnnotation typeAnnotation) {
  
negative.code:         tryMakeConstructorNamePlaceholder(implementingFactory.cachedNode,
              element.getEnclosingClass());
        }
      } else if (element.isTopLevel()) {
        // Note: this code should only rename private identifiers for class'
        // fields/getters/setters/methods.  Top-level identifiers are renamed
        // just to escape conflicts and that should be enough as we shouldn't
        // be able to resolve private identifiers for other libraries.
        makeElementPlaceholder(node.name, element);
      }
    }
  
    void collectFieldDeclarationPlaceholders(
        Element element, VariableDefinitions node) {
      if (element.isTopLevel()) {
        Node fieldNode = element.parseNode(compiler);
        if (fieldNode is Identifier) {
          makeElementPlaceholder(fieldNode, element);
  