Is gddoc or gdoc supported?

I just need to know if gdoc or gddoc files are supported within LibreOffice? I use Insync to sync all my Goolge Drive files but need to open them when I am offline and I really want to be able to open those files using LibreOffice.

So, is gddoc or gdoc files supported by LibreOffice?

Thanks.

Please see this blog post about why there’s no such thing as google docs file.