public async Task SelectSpecificationForFunding_GivenNoFundingStreamAlreadySelectedInPeriod_ReturnsConflict()
        {
            Specification specification = CreateSpecification();
            Specification specificationWithFundingStreamClash = CreateSpecification();

            SpecificationVersion currentVersionOfSpecification = specification.Current;

            string commonFundingStreamId = currentVersionOfSpecification.FundingStreams.First().Id;

            specificationWithFundingStreamClash.Current.FundingStreams.First().Id = commonFundingStreamId;

            ISpecificationsRepository specificationsRepository = CreateSpecificationsRepository();

            specificationsRepository
            .GetSpecificationById(SpecificationId)
            .Returns(specification);
            specificationsRepository
            .GetSpecificationsSelectedForFundingByPeriod(currentVersionOfSpecification.FundingPeriod.Id)
            .Returns(new[] { specificationWithFundingStreamClash });

            IActionResult result = await CreateService(
                logs : CreateLogger(),
                specificationsRepository : specificationsRepository)
                                   .SelectSpecificationForFunding(SpecificationId);

            result
            .Should()
            .BeOfType <ConflictResult>();
        }