private StackVersionRequest getRequest(Map<String, Object> properties) {
    return new StackVersionRequest(
        (String) properties.get(STACK_NAME_PROPERTY_ID),
        (String) properties.get(STACK_VERSION_PROPERTY_ID));
  }
The key property ids for a mpack resource.
ambari-server/src/main/java/org/apache/ambari/server/controller/internal/StackVersionResourceProvider.java