public void checkNameServiceId(Configuration conf, String addr, String expectedNameServiceId) {
   InetSocketAddress s = NetUtils.createSocketAddr(addr);
   String nameserviceId =
       DFSUtil.getNameServiceIdFromAddress(
           conf, s, DFS_NAMENODE_SERVICE_RPC_ADDRESS_KEY, DFS_NAMENODE_RPC_ADDRESS_KEY);
   assertEquals(expectedNameServiceId, nameserviceId);
 }