code: @Override
      public String getTopologyConf(String id) throws TException {
          String rtn;
          try {
              Map<Object, Object> topologyConf = StormConfig.read_nimbus_topology_conf(id, data.getBlobStore());
              rtn = JStormUtils.to_json(topologyConf);
          } catch (IOException e) {
              LOG.info("Failed to get configuration of " + id, e);
              throw new TException(e);
          }
          return rtn;
      }
docs: get topology configuration
  
  @param id String: topology id
  @return String