code: public static AppEngineDescriptor parse(InputStream in) throws IOException, SAXException {
      Preconditions.checkNotNull(in, "Null input");
      try {
        DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
        documentBuilderFactory.setNamespaceAware(true);
        return new AppEngineDescriptor(documentBuilderFactory.newDocumentBuilder().parse(in));
      } catch (ParserConfigurationException exception) {
        throw new SAXException("Cannot parse appengine-web.xml", exception);
      }
    }
docs: Parses an appengine-web.xml file.
  
  @param in the contents of appengine-web.xml
  @return a fully parsed object that can be queried
  @throws IOException if parsing fails due to I/O errors
  @throws SAXException malformed XML