@Test(expected = IllegalArgumentException.class)
  public void testGetActiveIdentities_MissingCluster() throws Exception {
    testGetActiveIdentities(null, null, null, null, true, SecurityType.KERBEROS);
  }
Tests that when regenerating keytabs for an upgrade, that the retry allowed
boolean is set on the tasks created.

@throws Exception
ambari-server/src/test/java/org/apache/ambari/server/controller/KerberosHelperTest.java