public async void Details_Update_null()
        {
            Mock <IPipelineStepStepRequirementRepository> pipelineStepStepRequirementRepository = new Mock <IPipelineStepStepRequirementRepository>();

            pipelineStepStepRequirementRepository.Setup(x => x.Get(It.IsAny <int>())).Returns(Task.FromResult(new PipelineStepStepRequirement()));

            var validator = new ApiPipelineStepStepRequirementServerRequestModelValidator(pipelineStepStepRequirementRepository.Object);
            await validator.ValidateUpdateAsync(default(int), new ApiPipelineStepStepRequirementServerRequestModel());

            validator.ShouldHaveValidationErrorFor(x => x.Details, null as string);
        }
        public async void PipelineStepId_Update_Invalid_Reference()
        {
            Mock <IPipelineStepStepRequirementRepository> pipelineStepStepRequirementRepository = new Mock <IPipelineStepStepRequirementRepository>();

            pipelineStepStepRequirementRepository.Setup(x => x.PipelineStepByPipelineStepId(It.IsAny <int>())).Returns(Task.FromResult <PipelineStep>(null));

            var validator = new ApiPipelineStepStepRequirementServerRequestModelValidator(pipelineStepStepRequirementRepository.Object);

            await validator.ValidateUpdateAsync(default(int), new ApiPipelineStepStepRequirementServerRequestModel());

            validator.ShouldHaveValidationErrorFor(x => x.PipelineStepId, 1);
        }