synchronized ChoreService getChoreService() {
    if (isClosed()) {
      throw new IllegalStateException("connection is already closed");
    }
    if (choreService == null) {
      choreService = new ChoreService("AsyncConn Chore Service");
    }
    return choreService;
  }
If choreService has not been created yet, create the ChoreService.
hbase-client/src/main/java/org/apache/hadoop/hbase/client/AsyncConnectionImpl.java