public function toArray()
    {
        return [
            'id' => $this->id,
            'filename' => $this->filename,
            'filetype' => $this->filetype,
            'filesize' => $this->filesize,
            'tags' => $this->tags,
            'preview_url' => $this->previewUrl(),
            'url' => $this->downloadUrl()
        ];
    }