code: public Element parseError(final InputStream in) {
      try {
        final Document doc = parseContent(in);
  
        final Element root = doc.getDocumentElement();
  
        expect(root, WebdavTags.error);
  
        final List<Element> els = getChildren(root);
  
        if (els.size() != 1) {
          return null;
        }
  
        return els.get(0);
      } catch (final Throwable ignored) {
        return null;
      }
    }
docs: Parse a DAV error response
  
  @param in response
  @return a single error element or null