code: protected final void preInvoke(EJSDeployedSupport s)
                      throws TransactionRolledbackException
      {
          ensureActive();
  
          // Save previous method's tx 'began' indication, to be restored in
          // postInvoke, and set current method's 'began' indication from
          // uowCookie (result of tx collaborator).  Note that if there is no
          // uowCookie, then the tx collaborator was not called (i.e. running
          // in Lightweight mode) and so a tx was obviously not begun.     LI3795-56
          s.previousBegan = began;
          if (s.uowCookie == null) // LI3795-56
              began = false;
          else
              began = s.uowCookie.beganTx();
          s.began = began; // d156688
      }
docs: getBeanOs