EDIT

	 public UpdateResult addChildFeatureNode(FeatureNode node, Feature featureChild){

	     UpdateResult result = new UpdateResult();

	     FeatureNode childNode = FeatureNode.NewInstance(featureChild);

	     node.addChild(childNode);

	     result.addUpdatedObject(node);

	     return result;

            targetNode.addChild(movedNode, position);

        }

        result.addUpdatedObject(targetNode);

        if(parent!=null){

            result.addUpdatedObject(parent);

        }

        result.setCdmEntity(targetNode.getFeatureTree());

        return result;