Sets the publishing sequence number of the specified event to the value seqn. If your client wants to ensure the delivery of an event to the Broker, this function should be called to set the sequence number prior to publishing the event.

The Broker will discard any event with a non-zero sequence number if it has already processed an event with an equal or larger sequence number. Events with an event sequence number of zero are not subject to these rules. Sequence numbers have a 64-bit representation and, therefore, are never expected to wrap back to 1 or to repeat.