/**
   * Lifecycle method invoked when the consumer has destroyed. Erase the reference to the dropbox
   * low level client
   *
   * @throws Exception
   */
  @Override
  protected void doStop() throws Exception {
    if (configuration.getClient() == null) {
      configuration.setClient(null);

      LOG.info("consumer dropbox client deleted");
    }
    super.doStop();
  }
  /**
   * Lifecycle method invoked when the consumer has created. Internally create or reuse a connection
   * to the low level dropbox client
   *
   * @throws Exception
   */
  @Override
  protected void doStart() throws Exception {
    if (configuration.getClient() == null) {
      // create dropbox client
      configuration.createClient();

      LOG.info("consumer dropbox client created");
    }

    super.doStart();
  }