Calculated convtab stored in .cache dir stored with volumeID in file name instead of mediaKey

Dear libbdplus maintainer,

When a convtab could be successfully calculated, it is stored in ~/.cache/bdplus/<volumeID>/convtab.bin via bdplus_disc_cache_file(). But when searching for a cached convtab, bdplus_disc_findcachefile() looks for a file with the mediaKey in the file name. Is this intended?

Did I misunderstood something or is this maybe bug?

Thanks.