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 'package:analyzer/error/error.dart'
  -    show errorCodeValues, errorCodeByUniqueName;
   
   /**
    * An error code associated with an [AnalysisError].
  
positive.code:  */
  abstract class ErrorCode {
    /**
     * Engine error code values.
     */
    @deprecated
    static const List<ErrorCode> values = errorCodeValues;
  
    /**
     * An empty list of error codes.
     */
    @deprecated
    static const List<ErrorCode> EMPTY_LIST = const <ErrorCode>[];
  
    /**
     * The name of the error code.
     */
    final String name;
  
negative.code: 
    @override
    String toString() => uniqueName;
  }
  
  /**
  