private static function isInSubscriptionArray(\steam_calendar $steamCalendar, $subscriptions)
 {
     $steamCalendarId = $steamCalendar->get_id();
     foreach ($subscriptions as $subscription) {
         $id = $subscription->get_id();
         if ($id == $steamCalendarId) {
             return true;
         }
     }
     return false;
 }
 private static function isSteamCalendarEmpty(\steam_calendar $steamCalendar)
 {
     return count($steamCalendar->get_date_objects()) == 0;
 }