private static bool ValidateUser(UserDto user, List <ValidationResult> validationResults) { if (_userRegistrationService.UserNameExist(user.UserName)) { validationResults.Add(new ValidationResult("This username already exists.")); return(false); } if (_userRegistrationService.EmailExist(user.EmailAddress)) { validationResults.Add(new ValidationResult("This email address already registered.")); return(false); } return(true); }