public function groupBy($groupBy)
    {
        /** @var array $groupFields */
        $groupFields = func_get_args();

        if (count($groupFields) > 0) {
            parent::groupBy($this->alias(array_shift($groupFields)));

            foreach ($groupFields as $group) {
                $this->addGroupBy($group);
            }
        }

        return $this;
    }