@Test(timeout=5000)
public void testGetSpnegoKeytabKey() {

  HdfsConfiguration conf = new HdfsConfiguration();
  String defaultKey = "default.spengo.key";
  conf.unset(DFSConfigKeys.DFS_WEB_AUTHENTICATION_KERBEROS_KEYTAB_KEY);
  assertEquals("Test spnego key in config is null", defaultKey,
      DFSUtil.getSpnegoKeytabKey(conf, defaultKey));
  conf.set(DFSConfigKeys.DFS_WEB_AUTHENTICATION_KERBEROS_KEYTAB_KEY, "");
  assertEquals("Test spnego key is empty", defaultKey,
      DFSUtil.getSpnegoKeytabKey(conf, defaultKey));
  String spengoKey = "spengo.key";
  conf.set(DFSConfigKeys.DFS_WEB_AUTHENTICATION_KERBEROS_KEYTAB_KEY,
      spengoKey);
  assertEquals("Test spnego key is NOT null",
      DFSConfigKeys.DFS_WEB_AUTHENTICATION_KERBEROS_KEYTAB_KEY,
      DFSUtil.getSpnegoKeytabKey(conf, defaultKey));
}