public void setDefaultRealm(String defaultRealm) {
    this.defaultRealm = defaultRealm;
  }
Sets the administrator credentials for this KerberosOperationHandler.
<p/>
If the supplied {@link PrincipalKeyCredential} is not <code>null</code>, validates that the administrator
principal and values are not <code>null</code> or empty. If the credential value does not
validate, then a {@link KerberosAdminAuthenticationException} will be thrown.

@param administratorCredential the KDC administrator credential
@throws KerberosAdminAuthenticationException if the non-null Credential fails to contain
                                             a non-empty principal and password values.
ambari-server/src/main/java/org/apache/ambari/server/serveraction/kerberos/KerberosOperationHandler.java