public function cardinality($alias, $field = null, $script = null, $precision = null, $rehash = null)
    {
        $aggregation = new CardinalityAggregation($alias);

        $aggregation->setField($field);

        $aggregation->setScript($script);

        $aggregation->setPrecisionThreshold($precision);

        $aggregation->setRehash($rehash);

        $this->append($aggregation);
    }