public void GetAllUsers()
        {
            // Arrange
            ExternalService exService = new ExternalService();
            UserService service = new UserService(exService);

            using (var _session = DBSetup())
            {
                var userModel1 = new User()
                {
                    FirstName = "TestFN1",
                    LastName = "TestLN1",
                    Email = "*****@*****.**",
                    StreetAddress = "TestSA1",
                    City = "TestCity1",
                    State = "TestState1",
                    Zip = "99998"
                };
                _session.Store(userModel1);

                var userModel2 = new User()
                {
                    FirstName = "TestFN2",
                    LastName = "TestLN2",
                    Email = "*****@*****.**",
                    StreetAddress = "TestSA2",
                    City = "TestCity2",
                    State = "TestState2",
                    Zip = "99999"
                };
                _session.Store(userModel2);
                _session.SaveChanges();

                // Act
                List<User> result = service.GetAllUsers(_session);

                // Assert
                Assert.IsNotNull(result);
                Assert.AreEqual(result.Count, 2);
            }
        }