anchor.diff:    /// This is a suffix parser because it is assumed that type arguments have
     /// been parsed, or `listener.handleNoTypeArguments(..)` has been executed.
     Token parseLiteralFunctionSuffix(Token token) {
  -    // TODO(brianwilkerson) Return the last consumed token.
       Token next = token.next;
       assert(optional('(', next));
       Token closeBrace = closeBraceTokenFor(next);
  
positive.code:   }
  
    Token parseParenthesizedExpressionOrFunctionLiteral(Token token) {
      // TODO(brianwilkerson) Return the last consumed token.
      Token next = token.next;
      assert(optional('(', next));
      Token nextToken = closeBraceTokenFor(next).next;
  
negative.code:   /// ;
    /// ```
    Token parseConstExpression(Token token) {
      Token constKeyword = token.next;
      assert(optional('const', constKeyword));
      // TODO(brianwilkerson) Remove the invocation of `previous` when
  