code: private Document parseInputSource(InputSource s) throws JspException {
          try {
              DocumentBuilder db = XmlUtil.newDocumentBuilder();
              db.setEntityResolver(entityResolver);
              return db.parse(s);
          } catch (SAXException e) {
              throw new JspException(e);
          } catch (IOException e) {
              throw new JspException(e);
          }
      }
docs: Parses the given InputSource into a Document.