anchor.diff:          }
   
           forEachNode(code, onAssignment: (js.Assignment node) {
  -          js.Expression leftHandSide = node.leftHandSide;
  +          js.Expression leftHandSide = undefer(node.leftHandSide);
             if (leftHandSide is js.PropertyAccess) {
  -            js.Node selector = leftHandSide.selector;
  +            js.Node selector = undefer(leftHandSide.selector);
               String name;
               if (selector is js.Name) {
                 name = selector.key;
  
positive.code:         receiverName = 'this';
        }
  
        js.Node selector = node.selector;
        String name;
        if (selector is js.Name) {
          name = selector.key;
  
negative.code:     return null;
    }
  }
  
  js.Node undefer(js.Node node) {
    if (node is js.DeferredExpression) return undefer(node.value);
    if (node is ModularName) return undefer(node.value);
    return node;
  }
  