public ICollection <MeetingDto> CheckUsersAvailability(ICollection <int> userIds, DateTime from, DateTime to, int currentMeetingId)
{
foreach (int userId in userIds)
{
ValidationHelper.IntegerGreaterThanZero(userId, name: "User id");
}
ValidationHelper.IntegerGreaterThanZero(currentMeetingId, name: "Meeting id");
return(_meetingsRepository.CheckUsersAvailability(userIds, from, to, currentMeetingId));
}