private uint AddObserver()
 {
     if (null == this.RelayHandlerDelegate)
     {
         this.RelayHandlerDelegate = new vtkObjectEventRelay.RelayHandler(this.Execute);
     }
     return(vtkObjectEventRelay.vtkObjectEventRelay_AddObserver(base.GetCppThis(), (this.Sender == null) ? default(HandleRef) : this.Sender.GetCppThis(), this.EventId, this.RelayHandlerDelegate, 0f));
 }
 internal static extern uint vtkObjectEventRelay_AddObserver(HandleRef pThis, HandleRef sender, uint eventid, vtkObjectEventRelay.RelayHandler handler, float priority);