code: @Override
      public EventPipeline newEventPipeline(ExecutorService executorService) {
          return new CheckingPipelineFilter(
              new EventProcessor(tree(), executorService), channel());
      }
docs: /*
  (non-Javadoc)
  
  @see org.jgrapes.core.Manager#newEventPipeline(java.util.concurrent.
  ExecutorService)