code: public void setCancelAction(Action act) {
          if (act.entry != null && act.entry != this) {
              Log.e(TAG, "setCancelAction failed. Already applied to another notification - " +
                    act.entry.ID + ". Current notification is " + ID);
              return;
          }
          this.cancelAction = act;
          this.cancelAction.entry = this;
          this.cancelAction.title = "CancelAction";
      }
docs: Set a action to be fired when this notification gets canceled.
  
  @param act