public async Task <ActionResult <ICollection <SessionResponse> > > GetByConference(int conferenceId, DateTimeOffset?fromDate = null, DateTimeOffset?toDate = null) { fromDate = fromDate ?? DateTimeOffset.MinValue; toDate = toDate ?? DateTimeOffset.MaxValue; return((await _sessionsRepository.GetByConferenceIdAsync(conferenceId)) .Where(s => IsSessionWithinDateRange(fromDate, toDate, s)) .Select(m => m.MapSessionResponse()) .ToList()); }