JQuery sortable lists and fixed/locked items

Question

Is it possible to lock list items in JQuery sortable list in a way that those items will stay in that particular place in the list.

For example,

consider th

Answer 1

Maybe this will help to someone: use methods "disable" and "enable". Example HTML:

  
You can move me
  
You can't move me.

Script:

$('#sortable').sortable();
$('#sortable').mousedown(function() {
  if($(this).data('state')=='lifeless') $('#sortable').sortable('disable');
  else $('#sortable').sortable('enable');
});

Live example here: https://jsfiddle.net/ozsvar/0ggqtva5/2/