The role of this interceptor is to synchronize the state of the cache with
the underlying storage. It does this with the ejbLoad and ejbStore
semantics of the EJB specification. In the presence of a transaction this
is triggered by transaction demarcation. It registers a callback with the
underlying transaction monitor through the JTA interfaces. If there is no
transaction the policy is to store state upon returning from invocation.
The synchronization polices A,B,C of the specification are taken care of
here.
WARNING: critical code, get approval from senior developers
before changing.