title: Sortablejs - how can exclude element from sorting
body: <p>Using <code>Sortable.js</code> I'm trying to make only <code>Collapsible elements</code> change their order so if I move element #1 in the place of element #2 they don't affect the green line between them. I've tried <code>filter</code> option but it just blocks my green line element to be draggable but I can put any element in place of it which I want to block. Is it possible to make with library like that?</p>
  <p><a href="https://i.stack.imgur.com/07h6T.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/07h6T.png" alt="enter image description here" /></a></p>