src/Cache/KeyValueStorage.php
protected function eachKeys(array $keys, array $map, array $lookup)
    {
        foreach ($keys as $k) {
            $hash = sha1($k);
            $map[] = $hash;
            $lookup[$hash] = $k;
        }

        return [$map, $lookup];
    }
protected function eachKeys(array $keys, array $map, array $lookup)
    {
        foreach ($keys as $k) {
            $hash = sha1($k);
            $map[] = $hash;
            $lookup[$hash] = $k;
        }

        return [$map, $lookup];
    }
@param array $keys
@param array $map
@param array $lookup

@return array