public void RequestSchedule(string @class, bool refresh = false)
 {
     if (IsWeekClassSchduleLoading)
     {
         _provider.CancelGettingWeekScheduleForClass();
     }
     if (refresh)
     {
         IsRefreshing = true;
         _provider.GetWeekScheduleForClass(@class);
         return;
     }
     if (CurrentClass == @class)
     {
         return;
     }
     if (ScheduleExistsForClass(@class))
     {
         CurrentClass = @class;
         return;
     }
     IsWeekClassSchduleLoading = true;
     _provider.GetWeekScheduleForClass(@class);
 }