jQuery nestedsortable disable/enable

Question

I'm using jQuery nestedsortable plugin for sorting ul list. But sometimes i need to disable and enable it. It was easy with ui sortable, but can't find way to do it with nested list.

I tried to use:

$("ul").unbind(".nestedSortable");

But then no way to enable it again. Thanks for help.

UPDATE: Analyzing plugin source code helps.

$(".tree ul").nestedSortable('destroy');

will fully destroy nested sortable instance.