public void GetUserExpenseById_UnauthorizedUser_Unauthorized()
        {
            var user = new ClaimsPrincipal(new ClaimsIdentity(new Claim[]
                                                              { }, "mock"));

            _expenseController.ControllerContext = new ControllerContext()
            {
                HttpContext = new DefaultHttpContext()
                {
                    User = user
                }
            };

            // Act
            ActionResult <ExpenseDto> result = _expenseController.GetUserExpenseById("TestUser", new Guid()).Result;
            var resultAsStatusCodeResult     = result.Result as StatusCodeResult;

            // Assert
            Assert.IsInstanceOf <UnauthorizedResult>(resultAsStatusCodeResult);
            Assert.IsTrue(resultAsStatusCodeResult.StatusCode == 401);
        }