code: @SuppressWarnings("checkstyle:illegalcatch")
    public void beforeTaskStart() throws TaskStartHandlerFailure {
      LOG.log(Level.FINEST, "Sending TaskStart event to the registered event handlers.");
      for (final EventHandler<TaskStart> startHandler : this.taskStartHandlers) {
        try {
          startHandler.onNext(this.taskStart);
        } catch (final Throwable throwable) {
          throw new TaskStartHandlerFailure(startHandler, throwable);
        }
      }
      LOG.log(Level.FINEST, "Done sending TaskStart event to the registered event handlers.");
    }
docs: Sends the TaskStart event to the handlers for it.