public async Task CreateAssignment_RightObjectPassed_ReturnsCreatedAtAction()
        {
            // Arrange
            var controller      = new DeckAssignmentsController(flashcardDbContextMock.Object, GetMockUserManager().Object, emailService, logger);
            var rightAssignment = new DeckAssignmentDTO
            {
                Deck = new DeckInfoDTO()
                {
                    Id          = 2,
                    Name        = "Teszt csomag 2",
                    Module      = Module.A,
                    Deck_number = 2,
                    Status      = DeckStatus.Approved
                },
                User = new UserDTO()
                {
                    Id    = "268e543e-2020-ue63-a111-98321798c21",
                    Email = "*****@*****.**",
                    Name  = "Teszt User 2",
                }
            };

            // Act
            var result = await controller.CreateDeckAssignment(rightAssignment);

            // Asssert
            Assert.IsType <CreatedAtActionResult>(result.Result);
        }
        public async Task CreateDeckAssignment_InvalidObjectPassed_ReturnsBadRequest()
        {
            // Arrange
            var controller = new DeckAssignmentsController(flashcardDbContextMock.Object, GetMockUserManager().Object, emailService, logger);
            var deckIdMissingAssignment = new DeckAssignmentDTO
            {
                Deck = new DeckInfoDTO()
                {
                    Id          = 2,
                    Name        = "Teszt csomag 2",
                    Module      = Module.A,
                    Deck_number = 2,
                    Status      = DeckStatus.Approved
                },
                User = new UserDTO()
                {
                    Id    = "268e543e-2020-ue63-a111-98321798c21",
                    Email = "*****@*****.**",
                    Name  = "Teszt User 2",
                }
            };

            controller.ModelState.AddModelError("DeckId", "Required");

            // Act
            var result = await controller.CreateDeckAssignment(deckIdMissingAssignment);

            // Asssert
            Assert.IsType <BadRequestObjectResult>(result.Result);
        }