public static Map<String, Object> createKerberosDescriptorRequestProperties(String clusterName) {
    return ImmutableMap.of(
      ArtifactResourceProvider.CLUSTER_NAME_PROPERTY, clusterName,
      ArtifactResourceProvider.ARTIFACT_NAME_PROPERTY, ArtifactResourceProvider.KERBEROS_DESCRIPTOR
    );
  }
@return {@code Optional} with the cluster's kerberos descriptor artifact if it exists, otherwise empty {@code Optional}
ambari-server/src/main/java/org/apache/ambari/server/topology/addservice/ResourceProviderAdapter.java