code: @SuppressWarnings("checkstyle:illegalcatch")
    private void closeTask(final byte[] message) throws TaskCloseHandlerFailure {
      LOG.log(Level.FINEST, "Invoking close handler.");
      try {
        this.fCloseHandler.get().onNext(new CloseEventImpl(message));
      } catch (final Throwable throwable) {
        throw new TaskCloseHandlerFailure(throwable);
      }
    }
docs: Calls the configured Task close handler and catches exceptions it may throw.