code: @Private
    @Override
    public void cancelled(final int pTaskletId) {
      assert taskletId == pTaskletId;
  
      this.cancelled.set(true);
      if (callbackHandler != null) {
        executor.execute(new Runnable() {
          @Override
          public void run() {
            callbackHandler.onFailure(new InterruptedException("VortexFuture has been cancelled on request."));
          }
        });
      }
      this.countDownLatch.countDown();
    }
docs: Called by VortexMaster to let the user know that the Tasklet was cancelled.