anchor.diff:  
     int statementDepth = 0;
     Token parseStatementOpt(Token token) {
  +    // TODO(brianwilkerson) Accept the last consumed token.
  +    // TODO(brianwilkerson) Return the last consumed token.
       if (statementDepth++ > 500) {
         // This happens for degenerate programs, for example, a lot of nested
         // if-statements. The language test deep_nesting2_negative_test, for
  
positive.code:   /// Note: unlike most parse methods, this method returns the last token parsed
    /// (the closing brace) rather than the next token to be parsed.
    Token parseClassBody(Token token, Token beforeBody) {
      Token begin = token;
      listener.beginClassBody(token);
      if (!optional('{', token)) {
  
negative.code:   /// It's an error if there's no function body unless [allowAbstract] is true.
    Token parseAsyncOptBody(
        Token token, bool ofFunctionExpression, bool allowAbstract) {
      // TODO(brianwilkerson) Accept the last consumed token.
      // TODO(brianwilkerson) Return the last consumed token.
      AsyncModifier savedAsyncModifier = asyncState;
      token = parseAsyncModifier(token);
      token = parseFunctionBody(token, ofFunctionExpression, allowAbstract);
  