private void openRegion(RegionInfo hri) throws Exception {
    try {
      if (isRegionOpened(hri)) return;
    } catch (Exception e) {
    }
    // first version is '0'
    AdminProtos.OpenRegionRequest orr =
      RequestConverter.buildOpenRegionRequest(getRS().getServerName(), hri, null);
    AdminProtos.OpenRegionResponse responseOpen = getRS().getRSRpcServices().openRegion(null, orr);
    Assert.assertEquals(1, responseOpen.getOpeningStateCount());
    Assert.assertEquals(AdminProtos.OpenRegionResponse.RegionOpeningState.OPENED,
      responseOpen.getOpeningState(0));
    checkRegionIsOpened(hri);
  }
This copro is used to synchronize the tests.
hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestReplicasClient.java