Requirement: subscriber.durable.unsubscribe

TopicSessions provide the unsubscribe method for deleting a durable subscription created by their client. This deletes the state being maintained on behalf of the subscriber by its provider. It is erroneous for a client to delete a durable subscription while it has an active TopicSubscriber for it or while a message received by it is part of a current transaction or has not been acknowledged in the session. (Note: this last sentence suggests that a provider doesn't need to check that a client can remove a subscription)

See:

• Section 6.11.1, Durable Topic Subscriber