@Test
  public void testRegionReplicaReplicationWith3Replicas() throws Exception {
    testRegionReplicaReplication(3, false);
    testRegionReplicaReplication(3, true);
  }
Tests region replication by setting up region replicas and verifying async wal replication
replays the edits to the secondary region in various scenarios.
hbase-server/src/test/java/org/apache/hadoop/hbase/replication/regionserver/TestRegionReplicaReplication.java