code: function createDocumentFragment(ownerDocument, data){
      if (!ownerDocument) {
          ownerDocument = document;
      }
      if(supportsUnknownElements){
          return ownerDocument.createDocumentFragment();
      }
      data = data || getExpandoData(ownerDocument);
      var clone = data.frag.cloneNode(),
          i = 0,
          elems = getElements(),
          l = elems.length;
      for(;i<l;i++){
          clone.createElement(elems[i]);
      }
      return clone;
    }
docs: returns a shived DocumentFragment for the given document
  @memberOf html5
  @param {Document} ownerDocument The context document.
  @returns {Object} The shived DocumentFragment.