anchor.diff:    /// is not a function-typed field formal parameter.
     FormalParameterList get parameters;
   
  +  /// Set the parameters of the function-typed parameter to the given
  +  /// [parameters].
  +  void set parameters(FormalParameterList parameters);
  +
  +  /// Return the token representing the period.
  +  Token get period;
  +
  +  /// Set the token representing the period to the given [token].
  +  void set period(Token token);
  +
     /// If the parameter is function-typed, and has the question mark, then its
     /// function type is nullable. Having a nullable function type means that the
     /// parameter can be null.
     Token get question;
  -
  -  /// Set the parameters of the function-typed parameter to the given
  -  /// [parameters].
  -  void set parameters(FormalParameterList parameters);
  -
  -  /// Return the token representing the period.
  -  Token get period;
  -
  -  /// Set the token representing the period to the given [token].
  -  void set period(Token token);
   
     /// Return the token representing the 'this' keyword.
     Token get thisKeyword;
  
positive.code: /// When an AST is resolved, the identifiers in the AST will be associated with
  /// the elements that they refer to and every expression in the AST will have a
  /// type associated with it.
  import 'package:analyzer/dart/ast/syntactic_entity.dart';
  import 'package:analyzer/dart/ast/token.dart';
  import 'package:analyzer/dart/element/element.dart';
  
negative.code: // Copyright (c) 2014, 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.
  
  /// Defines the AST model. The AST (Abstract Syntax Tree) model describes the
  /// syntactic (as opposed to semantic) structure of Dart code. The semantic
  