userRegister method Null safety

Future<void> userRegister(
  1. {required String? username,
  2. required String? password,
  3. String? nickname}
)

Implementation

Future<void> userRegister(
    {required String? username,
    required String? password,
    String? nickname}) async {
  print("Action - userRegister: username=$username,pw=$password");
  await _channel.invokeMethod('userRegister',
      {'username': username, 'password': password, 'nickname': nickname});
}