Dart optional function parameter experiment

optional_parameter.dart

void namedParameter(String param1, String param2,
    {bool enable, bool bold = false, bool hidden = false}) {
  print("namedParameter:param1=${param1}");
  print("namedParameter:param2=${param2}");
  print("namedParameter:enable=${enable}");
  print("namedParameter:bold=${bold}");
  print("namedParameter:hidden=${hidden}");
  print("--");
}

void positionalParameter(String param1, String param2,
    [bool enable, bool bold = false, bool hidden = false]) {
  print("positionalParameter:param1=${param1}");
  print("positionalParameter:param2=${param2}");
  print("positionalParameter:enable=${enable}");
  print("positionalParameter:bold=${bold}");
  print("positionalParameter:hidden=${hidden}");
  print("--");
}

void main() {
  namedParameter("TEST-1a", "TEST-1b");
  namedParameter("TEST-2a", "TEST-2b", bold: true);
  namedParameter("TEST-3a", "TEST-3b", bold: true, enable: true);
  // namedParameter("TEST-4a", "TEST-4b", true, bold: true); // ERR
  positionalParameter("TEST-1a", "TEST-1b");
  positionalParameter("TEST-2a", "TEST-2b", true);
  positionalParameter("TEST-3a", "TEST-3b", true, true);
}