INTERNAL:
This method will be used to check for a transaction and throws exception if none exists.
If this methiod returns without exception then a transaction exists.
This method must be called before accessing the localUOW.
public void
clear()
INTERNAL:
Clears the transactional UnitOfWork
if (this.localUOW != null){
// all change sets and cache are cleared
this.localUOW.clear(true);
}
INTERNAL:
THis method is used to get the active UnitOfWork. It is special in that it will
return the required RepeatableWriteUnitOfWork required by the EntityManager. Once
RepeatableWrite is merged into existing UnitOfWork this code can go away.
Mark the current transaction so that the only possible
outcome of the transaction is for the transaction to be
rolled back.
This is an internal method and if the txn is not active will do nothing
