xid = null;
     public void internalBegin() throws ResourceException {         if (xid != null)              throw new FBResourceTransactionException(                     "Local transaction active: can't begin another",                     FBResourceTransactionException.SQL_STATE_TRANSACTION_ACTIVE);                  xid = new FBLocalXid();                  synchronized(mc) {             try {                 mc.internalStart(xid, XAResource.TMNOFLAGS);             } catch(XAException ex) {                 throw new FBResourceException(ex);             } catch(GDSException ex) {                 throw new FBResourceException(ex);             }                          if (beginEvent != null)                  mc.notify(                         FBManagedConnection.localTransactionStartedNotifier,                          beginEvent);         }     }