anchor.diff:    /// Return the native clause for this class, or `null` if the class does not
     /// have a native clause.
     NativeClause? get nativeClause;
  -
  -  /// Return the with clause for the class, or `null` if the class does not have
  -  /// a with clause.
  -  WithClause? get withClause;
   
     /// Return the constructor declared in the class with the given [name], or
     /// `null` if there is no such constructor.
  
positive.code:   Token get name;
  }
  
  /// The declaration of a class.
  ///
  ///    classDeclaration ::=
  ///        'abstract'? 'class' [SimpleIdentifier] [TypeParameterList]?
  ///        ([ExtendsClause] [WithClause]?)?
  ///        [ImplementsClause]?
  ///        '{' [ClassMember]* '}'
  ///
  /// Clients may not extend, implement or mix-in this class.
  abstract class ClassDeclaration implements ClassOrMixinDeclaration {
    /// Return the 'abstract' keyword, or `null` if the keyword was absent.
    Token? get abstractKeyword;
  
    /// Return the token representing the 'class' keyword.
    Token get classKeyword;
  
    /// Return the extends clause for this class, or `null` if the class does not
    /// extend any other class.
    ExtendsClause? get extendsClause;
  
    /// Return `true` if this class is declared to be an abstract class.
    @Deprecated('Use abstractKeyword instead')
    bool get isAbstract;
  
negative.code: 
    /// Returns the members defined by the class/mixin.
    NodeList<ClassMember> get members;
  
    /// Returns the right curly bracket.
    Token get rightBracket;
  