validate property

Implementation

@override
String? get validate {
  if (amount2 != null && amount == null) {
    return "Must set amount with amount2";
  } else if (ePrice != null && amount == null) {
    return "Must set amount with e_price";
  } else if (lpTokenOut != null && amount == null) {
    return "Must set at least lp_token_out or amount";
  }
  return super.validate;
}