subscription property

The subscription whose backlog the snapshot retains.

Specifically, the created snapshot is guaranteed to retain: (a) The existing backlog on the subscription. More precisely, this is defined as the messages in the subscription's backlog that are unacknowledged upon the successful completion of the CreateSnapshot request; as well as: (b) Any messages published to the subscription's topic following the successful completion of the CreateSnapshot request. Format is projects/{project}/subscriptions/{sub}.

Required.