<?php

namespace Ddrv\Extra;

interface PackInterface
{
    /**
     * @param string $key
     * @param mixed $minimal
     * @param mixed $maximal
     * @return string
     */
    public static function getOptimalFormat($key, $minimal, $maximal);
}

<?php

$optimalFormat = \Ddrv\Extra\Pack::getOptimalFormat('articles', 100322, 100500);
echo $optimalFormat;