public void EditCentreDetailsPostSave_without_previewing_signature_image_fails_validation()
        {
            // Given
            var model = new EditCentreDetailsViewModel
            {
                NotifyEmail         = "*****@*****.**",
                BannerText          = "Banner text",
                CentreSignatureFile = A.Fake <FormFile>(),
            };

            // When
            var result = controller.EditCentreDetails(model, "save");

            // Then
            A.CallTo(
                () => centresDataService.UpdateCentreDetails(
                    A <int> ._,
                    A <string> ._,
                    A <string> ._,
                    A <byte[]?> ._,
                    A <byte[]?> ._
                    )
                )
            .MustNotHaveHappened();
            result.As <ViewResult>().Model.Should().BeEquivalentTo(model);
            controller.ModelState[nameof(EditCentreDetailsViewModel.CentreSignatureFile)].ValidationState.Should()
            .Be(ModelValidationState.Invalid);
        }