AdminLTE.tree navigation click how to expand all

how do I expand all using AdminLTE.tree navigation?

currently AdminLTE.tree sidebar navigation, click on one menu and another active menu to automatically collapse. Is it possible not to fold automatically? Please give me some advice.

code is as follows:

/ * Tree ()

=
Converts the sidebar into a multilevel
tree view menu.

@ type Function
@ Usage: $.AdminLTE.tree (".sidebar")

* /
$.AdminLTE.tree = function (menu) {

var _this = this;
var animationSpeed = $.AdminLTE.options.animationSpeed;
$(document).off("click", menu + " li a")
  .on("click", menu + " li a", function (e) {
    //Get the clicked link and the next element
    var $this = $(this);
    var checkElement = $this.next();

    //Check if the next element is a menu and is visible
    if ((checkElement.is(".treeview-menu")) && (checkElement.is(":visible")) && (!$("body").hasClass("sidebar-collapse"))) {
      //Close the menu
      checkElement.slideUp(animationSpeed, function () {
        checkElement.removeClass("menu-open");
        //Fix the layout in case the sidebar stretches over the height of the window
        //_this.layout.fix();
      });
      checkElement.parent("li").removeClass("active");
    }
    //If the menu is not visible
    else if ((checkElement.is(".treeview-menu")) && (!checkElement.is(":visible"))) {
      //Get the parent menu
      var parent = $this.parents("ul").first();
      //Close all open menus within the parent
      var ul = parent.find("ul:visible").slideUp(animationSpeed);
      //Remove the menu-open class from the parent
      ul.removeClass("menu-open");
      //Get the parent li
      var parent_li = $this.parent("li");

      //Open the target menu and add the menu-open class
      checkElement.slideDown(animationSpeed, function () {
        //Add the class active to the parent li
        checkElement.addClass("menu-open");
        parent.find("li.active").removeClass("active");
        parent_li.addClass("active");
        //Fix the layout in case the sidebar stretches over the height of the window
        _this.layout.fix();
      });
    }
    //if this isn"t a link, prevent the page from being redirected
    if (checkElement.is(".treeview-menu")) {
      e.preventDefault();
    }
  });

};