@Override
  public Result postIncrement(final ObserverContext<? extends RegionCoprocessorEnvironment> c,
    final Increment increment, final Result result) throws IOException {
    ctPostIncrement.incrementAndGet();
    return result;
  }
A sample region observer that tests the RegionObserver interface. It works with
TestRegionObserverInterface to provide the test case.
hbase-server/src/test/java/org/apache/hadoop/hbase/coprocessor/SimpleRegionObserver.java