src/Builder/Syntax/SelectWriter.php
public function writeSelectGroupBy(Select $select, array &$parts)
    {
        $groupBy = $this->writeSelectAggrupation(
            $select,
            $this->columnWriter,
            'getGroupBy',
            'writeColumn',
            ', ',
            'GROUP BY '
        );

        $parts = \array_merge($parts, [$groupBy]);

        return $this;
    }
public function writeSelectGroupBy(Select $select, array &$parts)
    {
        $groupBy = $this->writeSelectAggrupation(
            $select,
            $this->columnWriter,
            'getGroupBy',
            'writeColumn',
            ', ',
            'GROUP BY '
        );

        $parts = \array_merge($parts, [$groupBy]);

        return $this;
    }
@param Select $select
@param array  $parts

@return $this