internal DraftApprenticeship GetDraftApprenticeship(long draftApprenticeshipId)
{
var existingDraftApprenticeship = DraftApprenticeships.SingleOrDefault(a => a.Id == draftApprenticeshipId);
if (existingDraftApprenticeship == null)
{
throw new InvalidOperationException($"There is not a draft apprenticeship with id {draftApprenticeshipId} in cohort {Id}");
}
return(existingDraftApprenticeship);
}
