public async Task OnPostAsync_PopulatesThePageModel_WithAnAssignment()
        {
            // Arrange
            var pageModel = new CreateModel(MockAppDbContext.Object)
            {
                Assignment = ApplicationDbContext.GetSeedingAssignments().First(a => a.Id == 1),
                AssignmentSpecificationUpload     = UploadReferenceAssignment,
                ReferenceSolutionUpload           = UploadReferenceTestCases,
                ReferenceTestCasesSolutionsUpload = UploadReferenceTestCasesSolutions
            };

            pageModel.Assignment.Id   = 0;
            pageModel.Assignment.Name = "Newly created assignment";

            pageModel.ApplicationModes = await pageModel.GetApplicationModes(null);

            pageModel.CoverageTypeOptions = await pageModel.GetCoverageTypeOptions(null);


            // Act
            await pageModel.OnPostAsync();

            // Assert
            var assignments = await MockAppDbContext.Object.GetAssignmentsAsync();

            var actualAssignment = Assert.IsAssignableFrom <Assignment>(assignments.FirstOrDefault(a => a.Name == "Newly created assignment"));

            Assert.NotNull(actualAssignment);
        }