code: function () {
              var self = this;
              if (!self.isChildrenFiltered) {
                  var writer = new (module.require('html-parser/writer/basic'))();
                  self._writeChildrenHTML(writer);
                  var parser = new (module.require('html-parser/parser'))(writer.getHtml()), children = parser.parse().childNodes;
                  self.empty();
                  util.each(children, function (c) {
                      self.appendChild(c);
                  });
                  self.isChildrenFiltered = 1;
              }
          }
docs: give root node a chance to filter children first