Namshi\AB\Test::calculateVariation PHP Method

    protected function calculateVariation()
    {
        if ($this->getSeed()) {
            mt_srand($this->getSeed());
        }
        $sum = 0;
        $max = array_sum($this->getVariations());
        $random = mt_rand(1, $max);
        foreach ($this->getVariations() as $variation => $odd) {
            $sum += $odd;
            if ($random <= $sum) {
                $this->variation = $variation;
                return;
            }
        }
    }