public function mix(array $parts)
    {
        if (empty($parts)) {
            return '';
        }
        $len        = Util::safeStrlen($parts[0]);
        $parts      = $this->normalizeParts($parts);
        $stringSize = count($parts[0]);
        $partsSize  = count($parts);
        $result     = '';
        $offset     = 0;
        for ($i = 0; $i < $stringSize; $i++) {
            $stub = $parts[$offset][$i];
            for ($j = 1; $j < $partsSize; $j++) {
                $newKey = $parts[($j + $offset) % $partsSize][$i];
                //Alternately mix the output for each source
                if ($j % 2 == 1) {
                    $stub ^= $this->mixParts1($stub, $newKey);
                } else {
                    $stub ^= $this->mixParts2($stub, $newKey);
                }
            }
            $result .= $stub;
            $offset  = ($offset + 1) % $partsSize;
        }

        return Util::safeSubstr($result, 0, $len);
    }