private Set<String> getAvailableServiceNames() {
    if (availableServices.isEmpty()) {
      return Collections.emptySet();
    } else {
      Set<String> serviceNames = new HashSet<>();

      Map<String, ManifestService> manifest = buildManifest();

      for (AvailableServiceReference ref : availableServices) {
        ManifestService ms = manifest.get(ref.serviceIdReference);
        serviceNames.add(ms.serviceName);
      }

      return serviceNames;
    }
  }
Gets the set of services that are included in this XML
@return an empty set for STANDARD repositories, or a non-empty set for PATCH type.
ambari-server/src/main/java/org/apache/ambari/server/state/repository/VersionDefinitionXml.java