public async Task <Alias> GetSingleAliasAsync(int?id, bool includeAll = false) { if (id == null) { throw new NullIdException("No id specified"); } var alias = await _context.GetAliases(includeAll).Extension().SingleOrDefaultAsync(a => a.ID == id); if (alias == null) { throw new IdNotFoundException($"No alias found for ID = {id}"); } return(alias); }