This is the interface for a Replication Tracker. A replication tracker provides the facility to
subscribe and track events that reflect a change in replication state. These events are used by
the ReplicationSourceManager to coordinate replication tasks such as addition/deletion of queues
and queue failover. These events are defined in the ReplicationListener interface. If a class
would like to listen to replication events it must implement the ReplicationListener interface
and register itself with a Replication Tracker.