anchor.diff:            'Should never make element placeholder for dynamic type element',
             node);
       }
  -    elementNodes.putIfAbsent(element, () => new Set<Node>()).add(node);
  +    elementNodes.putIfAbsent(element, () => new Set<Identifier>()).add(node);
     }
   
     void makePrivateIdentifier(Identifier node) {
  
positive.code:   }
  
    void makeTypePlaceholder(Node node, DartType type) {
      makeElementPlaceholder(node, type.element);
    }
  
  
negative.code:   PlaceholderCollector(this.compiler, this.fixedMemberNames, this.elementAsts) :
        nullNodes = new Set<Node>(),
        unresolvedNodes = new Set<Identifier>(),
        elementNodes = new Map<Element, Set<Identifier>>(),
        functionScopes = new Map<FunctionElement, FunctionScope>(),
        privateNodes = new Map<LibraryElement, Set<Identifier>>(),
        declarationTypePlaceholders = new List<DeclarationTypePlaceholder>(),
  