private void checkCommitAndNoData(Region<String, String> rgn) {
        assertThat(rgn.getEntry("key")).isNull();
        CacheTransactionManager txMgr2 = getCache().getCacheTransactionManager();
        MyTransactionListener tl = firstTransactionListenerFrom(txMgr2);
        tl.assertCounts();
        assertThat(TxEventTestUtil.getCreateEvents(tl.lastEvent.getEvents())).isEmpty();
        assertThat(TxEventTestUtil.getPutEvents(tl.lastEvent.getEvents())).isEmpty();
        assertThat(tl.lastEvent.getCache()).isEqualTo(rgn.getRegionService());
      }
Clear all existing transaction listeners and install the given listener.
geode-dunit/src/main/java/org/apache/geode/cache30/MultiVMRegionTestCase.java