anchor.diff:          receiverName = 'this';
         }
   
  -      js.Node selector = node.selector;
  +      js.Node selector = undefer(node.selector);
         String name;
         if (selector is js.Name) {
           name = selector.key;
  
positive.code:   void registerCalls(Features features, String tag, js.Node node,
        {String prefix = '', Set<js.PropertyAccess> handledAccesses}) {
      forEachNode(node, onCall: (js.Call node) {
        js.Node target = node.target;
        if (target is js.PropertyAccess) {
          js.Node selector = target.selector;
          bool fixedNameCall = false;
          String name;
          if (selector is js.Name) {
  
negative.code: import 'package:async_helper/async_helper.dart';
  import 'package:compiler/src/closure.dart';
  import 'package:compiler/src/common.dart';
  import 'package:compiler/src/common/codegen.dart';
  import 'package:compiler/src/compiler.dart';
  import 'package:compiler/src/diagnostics/diagnostic_listener.dart';
  import 'package:compiler/src/elements/entities.dart';
  