public static String getClientHostName(AlluxioConfiguration conf) {
    if (conf.isSet(PropertyKey.USER_HOSTNAME)) {
      return conf.getString(PropertyKey.USER_HOSTNAME);
    }
    return getLocalHostName((int) conf.getMs(PropertyKey.NETWORK_HOST_RESOLUTION_TIMEOUT_MS));
  }
@Test
  public void getConfiguredClientHostname() {
    mConfiguration.set(PropertyKey.USER_HOSTNAME, "clienthost");
    assertEquals("clienthost", NetworkAddressUtils.getClientHostName(mConfiguration));
  }