docs: function removeUnreferencedIDs() {
    var identifiedElements = $('[id]');
    var referencedIDs = findReferencedElements();
    _(identifiedElements).each(function(node) {
        var $node = $(node);
        var id = $node.attr('id');
        if(!_(referencedIDs).has(id)) {
          $node.removeAttr('id');
        };
    });
  }