public void InsertNewUser(INewUserDto dto)
 {
     Context.Users.InsertOnSubmit(new User
     {
         Username     = dto.UserName,
         Password     = dto.Password,
         FullUserName = dto.FullUserName,
         CreationDate = DateTime.Now
     });
     Context.SubmitChanges();
 }
        public void AddNewUser(INewUserDto dto)
        {
            var getSimilarUser = _usersRepository.GetUserByUsername(dto.UserName);

            if (getSimilarUser != null)
            {
                throw new ArgumentException("Użytkownik o takiej nazwie już istnieje w bazie");
            }

            _usersRepository.InsertNewUser(dto);
        }