public CheckedRegistrationInfo(string userName, string password, string name, int?age) : base(_form.GetNextId(), userName, password, name, age) { if (!_form.Validate("UserName", userName)) { throw new ArgumentException("Checked field is not specified"); } if (!_form.Validate("Password", password)) { throw new ArgumentException("Checked field is not specified"); } if (!_form.Validate("Name", name)) { throw new ArgumentException("Checked field is not specified"); } if (!_form.Validate("Age", age)) { throw new ArgumentException("Checked field is not specified"); } }