code: private DavChild makeDavChild(final Collection<Element> responseElements) throws Throwable {
      if (responseElements == null) {
        // status 400
        return null;
      }
  
      DavChild dc = null;
  
      int count = 0; // validity
      for (Element resp: responseElements) {
        count++;
  
        if (XmlUtil.nodeMatches(resp, WebdavTags.responseDescription)) {
          // Has to be last
          if (responseElements.size() > count) {
            throw new Exception("Bad multstatus Expected " +
                                        "(response+, responsedescription?)");
          }
  
          continue;
        }
  
        if (!XmlUtil.nodeMatches(resp, WebdavTags.response)) {
          throw new Exception("Bad multstatus Expected " +
                                      "(response+, responsedescription?) found " + resp);
        }
  
        if (dc != null){
          throw new Exception("Bad multstatus Expected only 1 response");
        }
  
        dc = makeDavResponse(resp);
      }
  
      return dc;
    }
docs: Return the DavChild element for the targeted node.
  
  @param responseElements   null for a default set
  @return DavChild or null for not found
  @throws Throwable