public void Validate() { if (Name.IsNullOrEmpty()) { throw new CustomerInvalidException("Name should not be emtpy or null"); } if (Surname.IsNullOrEmpty()) { throw new CustomerInvalidException("Surname should not be emtpy or null"); } if (TelephoneNumber.IsNullOrEmpty()) { throw new CustomerInvalidException("TelephoneNumber should not be emtpy or null"); } if (Address.IsNull()) { throw new CustomerInvalidException("Address should not be null"); } Address.Validate(); }