Getting the capability data value to write to write to tar header

[rmohr]

Is there a way to access the data of security.capability?

I want to add capabilities to files in a tar archive. This library would do exactly what I need, except that it seems like there is no way to get the actual data. I only found setVfsCap which directly sets it on a file. It would be great if there would be something like VFSCap() []byte which would return a byte array which I can directly write into a PAXRecords from the golang tar library.