code: private Document parseBytesToDocument(String pid, byte[] bytes)
              throws InvalidContentModelException {
          try {
              DocumentBuilderFactory factory =
                      DocumentBuilderFactory.newInstance();
              factory.setNamespaceAware(true);
              DocumentBuilder builder = factory.newDocumentBuilder();
              return builder.parse(new ByteArrayInputStream(bytes));
          } catch (ParserConfigurationException e) {
              throw new InvalidContentModelException(pid, "Failed to parse "
                      + DS_COMPOSITE_MODEL, e);
          } catch (SAXException e) {
              throw new InvalidContentModelException(pid, "Failed to parse "
                      + DS_COMPOSITE_MODEL, e);
          } catch (IOException e) {
              throw new InvalidContentModelException(pid, "Failed to parse "
                      + DS_COMPOSITE_MODEL, e);
          }
      }
docs: Create a DOM document from the original XML.