@Override
          public void run() {
            try {
              Region rgn1a = getCache().createRegion(rgnName1, getRegionAttributes());
              Region rgn2 = getCache().createRegion(rgnName2, getRegionAttributes());
              Region rgn3 =
                  getCache().createRegion(rgnName3, getRegionAttributes(Scope.DISTRIBUTED_NO_ACK));
              rgn1a.create("key", null);
              rgn2.create("key", null);
              rgn3.create("key", null);
            } catch (CacheException e) {
              Assert.fail("While creating region", e);
            }
          }
Test the internal callbacks used for what else... testing
geode-core/src/distributedTest/java/org/apache/geode/cache30/TXDistributedDUnitTest.java