docs: public InstanceId getInstanceId()
      {
          if (m_instanceId == null)
          {
              try
              {
                  byte[] data =
                      m_zk.getData(CoreZK.instance_id, false, null);
                  JSONObject idJSON = new JSONObject(new String(data, "UTF-8"));
                  m_instanceId = new InstanceId(idJSON.getInt("coord"),
                          idJSON.getLong("timestamp"));
  
              }
              catch (Exception e)
              {
                  String msg = "Unable to get instance ID info from " + CoreZK.instance_id;
                  hostLog.error(msg);
                  throw new RuntimeException(msg, e);
              }
          }
          return m_instanceId;
      }