public List <RoborHistoric> GetRobors([FromQuery] DateTime?begin, [FromQuery] DateTime?end) { if (!begin.HasValue && !end.HasValue) { return(new List <RoborHistoric>(1) { _rateRepository.GetRoborRecent() }); } return(_rateRepository.GetRobors(begin ?? DateTime.MinValue, end ?? DateTime.MaxValue)); }