public function groupBy($field): IQueryBuilderHandler
    {
        if (($field instanceof Raw) === false) {
            $field = $this->addTablePrefix($field);
        }

        if (\is_array($field) === true) {
            $this->statements['groupBys'] = array_merge($this->statements['groupBys'], $field);
        } else {
            $this->statements['groupBys'][] = $field;
        }

        return $this;
    }