@Override
  public Stack createStack(String stackName, String stackVersion, AmbariManagementController managementController) throws AmbariException {
    return new Stack(stackName, stackVersion, managementController);
  }
Default implementation of StackFactory.

Calls the Stack constructor to create the Stack instance.
ambari-server/src/main/java/org/apache/ambari/server/topology/DefaultStackFactory.java