public async Task GetAllAsyncWhenNoRequirementsReturnsEmptyCollection()
{
//Arrange
var mockRequirementRepository = GetDefaultIRequirementRepositoryInstance();
var mockUnitOfWork = GetDefaultIUnitOfWorkInstance();
var requirementId = 200;
mockRequirementRepository.Setup(r => r.FindById(requirementId))
.Returns(Task.FromResult <Requirement>(null));
var service = new RequirementService(mockRequirementRepository.Object, mockUnitOfWork.Object);
//Act
RequirementResponse result = await service.GetByIdAsync(requirementId);
var message = result.Message;
//Assert
message.Should().Be("Requirement not found");
}