validate method

@override void validate()

Метод проверяет валидность данных

Implementation

@override
void validate() {
  assert(paymentId.length <= 20);

  final int? _amount = amount;
  if (_amount != null) {
    assert(_amount.length <= 10);
  }

  final String? _ip = ip;
  if (_ip != null) {
    assert(_ip.length >= 7 && _ip.length <= 45);
  }
}