@Override
  public EntityLock regionLock(final List<RegionInfo> regionInfo, final String description,
    final Abortable abort) {
    final LockServiceClient client =
      new LockServiceClient(conf, lockStub, asyncClusterConnection.getNonceGenerator());
    return client.regionLock(regionInfo, description, abort);
  }
For testing
@return whether all wal roll request finished for this regionserver
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java