code: protected void setParent(Object parent, Object child) {
          getProxyBuilder().getCurrentFactory().setParent(getProxyBuilder().getChildBuilder(), parent, child);
          Factory parentFactory = getProxyBuilder().getParentFactory();
          if (parentFactory != null) {
              parentFactory.setChild(getProxyBuilder().getCurrentBuilder(), parent, child);
          }
      }
docs: Strategy method to establish parent/child relationships.
  
  @param parent the object from the parent node
  @param child  the object from the child node