code: function (fn, create) {
    return subscribe.call(this, fn, function (value) {
      return Utils.trackNode(create(value));
    }, function (value) {
      this.value.replace(create(value));
    }).value.fragment;
  }
docs: Render and subscribe a single DOM node using a custom creation function.
  
  @param  {Function} fn
  @param  {Function} create
  @return {Node}