model: Add a swhid() method to RawExtrinsicMetadata.
All other hashable objects but ExtId have one.
It will be used by swh-deposit.
Migrated from D5237 (view on Phabricator)
Staging instance, all changes can be removed at any time
All other hashable objects but ExtId have one.
It will be used by swh-deposit.
Migrated from D5237 (view on Phabricator)