anchor.diff:      _assertArgumentRange(0, 0, SourceRange(15, 3), SourceRange(15, 1));
     }
   
  -  Future<void> test_argumentRange_first_trailingComma() async {
  +  Future<void> test_first_trailingComma() async {
       await resolveTestCode('''
   void f() {
     g(0, 1, );
  
positive.code:     _assertArgumentRange(0, 0, SourceRange(15, 4), SourceRange(15, 4));
    }
  
    Future<void> test_argumentRange_only_positional() async {
      await resolveTestCode('''
  void f() {
    g(0);
  
negative.code:     _assertArgumentRange(1, 1, SourceRange(16, 3), SourceRange(18, 1));
    }
  
    Future<void> test_last_trailingComma() async {
      await resolveTestCode('''
  void f() {
    g(0, 1, );
  