What does jquery ui destroy() need to destroy?

What does jquery ui destroy() need to destroy?

What exactly gets destroyed by calling $.Widget.prototype.destroy.apply( this, arguments ) ? Or, equivalently, what needs to be destroyed in the code for a widget's destroy method?  And  I have an app that uses several pages that have jQuery ui widgets, DOM elements, classes, etc.  As the user goes from one page to another I am expecting to have to destroy the widgets along the way to navigating to navigating among the pages.  Is that correct?