private void presenceAvailable(object sender, PresenceAvailableEventArgs e)
 {
     Commands.ReceiveTeacherStatus.Execute(new TeacherStatus
     {
         Conversation = e.presence.Where,
         Joining = e.presence.Joining,
         Slide = e.presence.Where,
         Teacher = e.presence.Who
     });
 }
 protected virtual void onPresenceAvailable(PresenceAvailableEventArgs e)
 { PresenceAvailable(this, e); }