Unstick and Stick two elements

[anthonybalmeo]

Do you have any suggestions of sticking and unsticking elements using the events sticky-start and sticky-end

  didInsertElement() {
    Ember.$('.sticky-nav').on('sticky-start', function() {
    Ember.$('.app-header').unstick();
    });

    Ember.$('.sticky-nav').on('sticky-end', function() {
      Ember.$('.app-header').sticky({
        zIndex: 50,
        wrapperClassName: 'app-header-sticky',
      });
    });
  },

I have something like this but when I call unstick consecutively, I get a Cannot read property 'stickyWrapper' of undefined. It still works but there's some step prior that errors out that I'm trying to figure out. Thoughts?