@Override
  public Set<SubResourceDefinition> getSubResourceDefinitions() {
    Set<SubResourceDefinition> setChildren = new HashSet<>();
    setChildren.add(new SubResourceDefinition(Resource.Type.StackVersion, null, false));
    return setChildren;
  }
Resource Definition for Mpack Resource types.
ambari-server/src/main/java/org/apache/ambari/server/api/resources/MpackResourceDefinition.java