code: @Nullable
    private static Node getNode(Document doc, String parentNodeName, String targetNodeName) {
      NodeList parentElements = doc.getElementsByTagNameNS(APP_ENGINE_NAMESPACE, parentNodeName);
      if (parentElements.getLength() > 0) {
        Node parent = parentElements.item(0);
        if (parent.hasChildNodes()) {
          for (int i = 0; i < parent.getChildNodes().getLength(); i++) {
            Node child = parent.getChildNodes().item(i);
            if (child.getNodeName().equals(targetNodeName)) {
              return child;
            }
          }
        }
      }
      return null;
    }
docs: Returns the first node found matching the given name contained within the parent node.