public function memory()
    {
        $usedInBytes   = $this->data['memory_usage']['used_memory'];
        $wastedInBytes = $this->data['memory_usage']['wasted_memory'];
        $sizeInBytes   = $usedInBytes + $wastedInBytes + $this->data['memory_usage']['free_memory'];
        return new Memory(
            $this->bytesToMb($usedInBytes),
            $this->bytesToMb($sizeInBytes),
            $this->bytesToMb($wastedInBytes)
        );
    }