anchor.diff:  // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
   // for details. All rights reserved. Use of this source code is governed by a
   // BSD-style license that can be found in the LICENSE file.
  -
  -import 'dart:collection';
   
   import 'package:source_span/source_span.dart';
   import 'package:string_scanner/string_scanner.dart';
  
positive.code:   ///
    /// It's possible the element will end up not being an [ElementAst].
    StandaloneTemplateAst parseElement(
        NgToken beginToken, Queue<String> tagStack) {
      var isTemplateElement = false;
  
      // Parse the element identifier.
  
negative.code:           childNodes.add(childAst);
          }
        }
        tagStack.removeLast();
      }
  
      if (isTemplateElement) {
  