public static void setKerberosHelper(KerberosHelper kerberosHelper) {
    KerberosKeytabController.kerberosHelper = kerberosHelper;
  }
Helper class to construct convenient wrappers around database entities related to kerberos.
ambari-server/src/main/java/org/apache/ambari/server/serveraction/kerberos/stageutils/KerberosKeytabController.java