public SealedSharedKey keyOf(SnapshotId id, String hostname, PublicKey sealingKey) {
        Snapshot snapshot = require(id, hostname);
        return resealKeyOf(snapshot, sealingKey);
    }
Returns the encryption key for snapshot, sealed with given public key
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/backup/Snapshots.java