@VisibleForTesting
  public long getPurgeIntervalNanos() {
    return this.purgeIntervalNanos;
  }
@Test (timeout=300000)
  public void testPurgeIntervalNanosConf() throws Exception {
    Configuration conf = new Configuration();
    conf.setInt(CommonConfigurationKeysPublic.
        IPC_SERVER_PURGE_INTERVAL_MINUTES_KEY, 3);
    Server server = new Server("0.0.0.0", 0, LongWritable.class,
            1, conf) {
      @Override
      public Writable call(
              RPC.RpcKind rpcKind, String protocol, Writable param,
              long receiveTime) throws Exception {
        return null;
      }
    };
    long purgeInterval = TimeUnit.NANOSECONDS.convert(3, TimeUnit.MINUTES);
    assertEquals(server.getPurgeIntervalNanos(), purgeInterval);
  }