@Override
  public void format(NamespaceInfo nsInfo, boolean force) throws IOException {
    QuorumCall<AsyncLogger, Void> call = loggers.format(nsInfo, force);
    try {
      call.waitFor(loggers.size(), loggers.size(), 0, timeoutMs,
          "format");
    } catch (InterruptedException e) {
      throw new IOException("Interrupted waiting for format() response");
    } catch (TimeoutException e) {
      throw new IOException("Timed out waiting for format() response");
    }
    
    if (call.countExceptions() > 0) {
      call.rethrowException("Could not format one or more JournalNodes");
    }
  }
@Test
  public void testFormat() throws Exception {
    QuorumJournalManager qjm = closeLater(new QuorumJournalManager(
        conf, cluster.getQuorumJournalURI("testFormat-jid"), FAKE_NSINFO));
    assertFalse(qjm.hasSomeData());
    qjm.format(FAKE_NSINFO, false);
    assertTrue(qjm.hasSomeData());
  }