code: function tagAncestors($context) {
          // If we don't do this they start doubling up on the second and subsequent refreshes
          find($context, 'preserves').removeAttr('data-apos-ajax-preserves');
          var $preserve = find($context, 'preserve');
          $preserve.each(function() {
            var $el = $(this);
            var level = 0;
            $el.parentsUntil($context).each(function() {
              var $ancestor = $(this);
              addPreserves($ancestor, $el, level);
              level++;
            });
          });
        }
docs: Tag ancestors of each preserved element as preserving it, in a way that uniquely tags them for each preserved element, including indicating how many generations removed they are, so that we can find equivalent parent elements between $old and $new