public void CreateUser_UsersShoulsHaveUniqueSalt()
        {
            // First user
            string username = "******";
            string password = "******";

            // Second user
            string username2 = "test2";
            string password2 = "password2";

            User testUser1 = signInService.CreateUser(username, password);
            User testUser2 = signInService.CreateUser(username2, password2);

            bool saltsEqual = testUser1.Salt.Equals(testUser2.Salt);

            Assert.False(saltsEqual);
        }