private RootServiceHostComponentRequest getRequest(Map<String, Object> properties) {
    return new RootServiceHostComponentRequest((String) properties.get(SERVICE_NAME_PROPERTY_ID),
                                               (String) properties.get(HOST_NAME_PROPERTY_ID),
                                               (String) properties.get(COMPONENT_NAME_PROPERTY_ID));
  }
The property ids for a RootServiceHostComponent resource.
ambari-server/src/main/java/org/apache/ambari/server/controller/internal/RootServiceHostComponentResourceProvider.java