code: private ReadOnlyDiscoveryClient getDiscoveryClient(Map<String, String> params) throws IOException {
          final UUID discoveryId = getDiscoveryId(params);
  
          final ReadOnlyDiscoveryClient discoveryClient = DISCO_CLIENTS.get(discoveryId);
  
          if (discoveryClient == null) {
              throw new IOException("No discovery client registered for id " + discoveryId);
          }
          return discoveryClient;
      }
docs: Locate the appropriate DiscoveryClient for a given discoveryId