code: static void initBuilder() {
  		try {
  			DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
  			docBuilderFactory.setNamespaceAware(true);
  			docBuilder = docBuilderFactory.newDocumentBuilder();
  		} catch (ParserConfigurationException ex) {
  			throw new RuntimeException(ex);
  		}
  	}
docs: Note DocumentBuilderFactory is documented to be non thread safe.
  TODO: code analysis, of potential concurrency issues.