oj-tree-view not expanding all

Hi, i'm trying to expand all my tree-view's nodes by using addAll. For some reason is not working.

This is my snipped code:

PageModule.prototype.expandTree = function (tree, label) {
debugger;
tree.expanded = new ojknockout_keyset_1.ObservableKeySet().add(["90"]);
tree.expanded.clear();
tree.expanded.addAll();
};

Debuggin, i can si keys is "all=true"

Apppreciate any help, you may offer