async def deleteBackup(self, backup, source):
    if (not backup.getSource(source.name())):
        return
    slug = backup.slug()
    (await source.delete(backup))
    backup.removeSource(source.name())
    if backup.isDeleted():
        del self.backups[slug]
async def deleteBackup(self, backup, source):
    if (not backup.getSource(source.name())):
        return
    slug = backup.slug()
    (await source.delete(backup))
    backup.removeSource(source.name())
    if backup.isDeleted():
        del self.backups[slug]