code: function () {
          return domManipulate(this, arguments, function (node) {
            // Either element or Shadow Root
            if (this.nodeType === 1 || (this.host && this.host.nodeType === 1)) {
              this.insertBefore(node, this.firstChild);
            }
          }, true);
        }
docs: Prepends the specified node/html or node set to the current set nodes.
  
  @method prepend
  @param {String/Element/Array/tinymce.dom.DomQuery} content Content to prepend to each element in set.
  @return {tinymce.dom.DomQuery} Current set.