_.mixin({
  'orderKeysBy': function (obj, comparator, order) {
    var keys = _.orderBy(_.keys(obj), function (key) {
      return comparator ? comparator(obj[key], key) : key;
    }, order);
  
    var values = _.map(keys, function (key) {
      return obj[key];
    });
    
    return _.zipObject(keys, values);
  }
});