Quote from javadoc (JB 3.2.1):
* Implementations of this interface are used for getting
* a transaction propagation context at the client-side.
* We need a specific implementation of this interface for
* each kind of DTM we are going to interoperate with. (So
* we may have 20 new classes if we are going to interoperate
* with 20 different kinds of distributed transaction
* The reason for having the methods in this interface return
* Object is that we do not really know what kind of transaction
* propagation context is returned.
The class is located in jboss-transaction.jar on the server and jboss-transaction-client.jar for clients.