public function write($mData, string $sKey = null): Item
    {
        //  Generate a key if one isn't explicitly specified
        if (is_null($sKey)) {
            $sKey = md5(microtime(true));
        }

        $sPath = $this->prepKey($sKey);

        file_put_contents($sPath, $mData);

        return $this->newItem($sKey);
    }