anchor.diff:  
     @override
     ForStatement visitForStatement(ForStatement node) => astFactory.forStatement(
  +      awaitKeyword: _mapToken(node.awaitKeyword),
         forKeyword: _mapToken(node.forKeyword),
         leftParenthesis: _mapToken(node.leftParenthesis),
         forLoopParts: _cloneNode(node.forLoopParts),
  
positive.code:   @override
    bool visitForElement(ForElement node) {
      ForElement other = _other as ForElement;
      return isEqualTokens(node.forKeyword, other.forKeyword) &&
          isEqualTokens(node.leftParenthesis, other.leftParenthesis) &&
          isEqualNodes(node.forLoopParts, other.forLoopParts) &&
          isEqualTokens(node.rightParenthesis, other.rightParenthesis) &&
  
negative.code:   bool visitForStatement(ForStatement node) {
      ForStatement toNode = this._toNode as ForStatement;
      return _and(
          _isEqualTokens(node.awaitKeyword, toNode.awaitKeyword),
          _isEqualTokens(node.forKeyword, toNode.forKeyword),
          _isEqualTokens(node.leftParenthesis, toNode.leftParenthesis),
          _isEqualNodes(node.forLoopParts, toNode.forLoopParts),
  