@Test
public void testCheckAvailabilityNeg() throws IOException {

  conf.setLong(DFSConfigKeys.DFS_NAMENODE_DU_RESERVED_KEY, Long.MAX_VALUE);
  NameNodeResourceChecker nb = new NameNodeResourceChecker(conf);
  assertFalse(
      "isResourceAvailable must return false if " +
          "disk usage is higher than threshold",
      nb.hasAvailableDiskSpace());
}