code: Future<?> flushAllTableQueues() throws InterruptedException {
          return m_es.submit(new Callable<Boolean>() {
              @Override
              public Boolean call() throws Exception {
                  loadTable(buildTable(), m_table);
                  return true;
              }
          });
      }
docs: Flush all queued rows even if they are smaller than the batch size. This does not
  guarantee that they will be reinserted if any of them fail. To make sure all rows
  are either inserted or failed definitively, call shutdown().