public void postCompletedSplitRegionAction(final RegionInfo regionInfoA,
    final RegionInfo regionInfoB, final User user) throws IOException {
    execOperation(coprocEnvironments.isEmpty() ? null : new MasterObserverOperation(user) {
      @Override
      public void call(MasterObserver observer) throws IOException {
        observer.postCompletedSplitRegionAction(this, regionInfoA, regionInfoB);
      }
    });
  }
Invoked just after a split
@param regionInfoA the new left-hand daughter region
@param regionInfoB the new right-hand daughter region
@param user        the user
hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterCoprocessorHost.java