docs: public void waitForAllHostsToBeReady(int expectedHosts) {
          try {
              m_zk.create(CoreZK.readyhosts_host, null, Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL_SEQUENTIAL);
              while (true) {
                  ZKUtil.FutureWatcher fw = new ZKUtil.FutureWatcher();
                  int readyHosts = m_zk.getChildren(CoreZK.readyhosts, fw).size();
                  if ( readyHosts == expectedHosts) {
                      break;
                  }
                  fw.get();
              }
          } catch (KeeperException | InterruptedException e) {
              org.voltdb.VoltDB.crashLocalVoltDB("Error waiting for hosts to be ready", false, e);
          }
      }