code: void normalize(String expression)
      {
          final XPath xPath = XPathFactory.newInstance().newXPath();
          try
          {
              final NodeList nodeList = (NodeList) xPath.evaluate(expression, document, XPathConstants.NODESET);
              for (int i = 0; i < nodeList.getLength(); ++i)
              {
                  final Node node = nodeList.item(i);
                  node.getParentNode().removeChild(node);
              }
          }
          catch (final XPathExpressionException exception)
          {
              Verbose.exception(exception);
          }
      }
docs: Normalize document.
  
  @param expression The expression to evaluate (must not be <code>null</code>).