Basic operations: deleting nodes
function (obj) {
        obj = this._get_node(obj);
        if(!obj.length) { return false; }
        this.__rollback();
        var p = this._get_parent(obj), prev = this._get_prev(obj);
        obj = obj.remove();
        if(p !== -1 && p.find("> ul > li").length === 0) {
          p.removeClass("jstree-open jstree-closed").addClass("jstree-leaf");
        }
        this.clean_node(p);
        this.__callback({ "obj" : obj, "prev" : prev });
        return obj;
      }