anchor.diff:      implements EnumDeclaration {
     /// The 'enum' keyword.
     @override
  -  Token enumKeyword;
  +  final Token enumKeyword;
   
     /// The type parameters, or `null` if the enumeration does not have any
     /// type parameters.
  
positive.code: class ListLiteralImpl extends TypedLiteralImpl implements ListLiteral {
    /// The left square bracket.
    @override
    Token leftBracket;
  
    /// The expressions used to compute the elements of the list.
    final NodeListImpl<CollectionElement> _elements = NodeListImpl._();
  
    /// The right square bracket.
    @override
    Token rightBracket;
  
    /// Initialize a newly created list literal. The [constKeyword] can be `null`
    /// if the literal is not a constant. The [typeArguments] can be `null` if no
  
negative.code:   /// The token representing the 'final', 'const' or 'var' keyword, or `null` if
    /// no keyword was included.
    @override
    final Token? keyword;
  
    /// The token representing the 'late' keyword, or `null` if the late modifier
    /// was not included.
    @override
    final Token? lateKeyword;
  
    /// The type of the variables being declared, or `null` if no type was
    /// provided.
  