public static function getBiggerValue(array $values, $returnKey = false)
    {
        $bigger = null;

        foreach ($values as $k => $value) {
            if ($bigger === null || $value['size'] > $values[$bigger]['size']) {
                $bigger = $k;
            }
        }

        if ($bigger !== null) {
            return $returnKey ? $bigger : $values[$bigger]['value'];
        }
    }