private void HandleEndJoin(User[] list)
 {
     if (list == null)
     {
         ExitChatSession();
     }
     else
     {
         ProxyEventArgs e = new ProxyEventArgs {
             list = list
         };
         OnProxyEvent(e);
     }
 }
 public void OnProxyEvent(ProxyEventArgs e)
 {
     ProxyEvent?.Invoke(this, e);
 }