pingIntervalMillis = client.pingIntervalMillis,
          retryOnConnectionFailure = client.retryOnConnectionFailure,
          fastFallback = client.fastFallback,
          address = client.address(request.url),
          connectionUser = CallConnectionUser(this, connectionPool.connectionListener, chain),
          routeDatabase = client.routeDatabase,
        )
      this.exchangeFinder =
        when {

        });
    }

    /**
     * Creates an HTTP client for connecting to the search engine.
     *
     * @param fessConfig the Fess configuration
     * @param host       the search engine host address
     * @return the configured HTTP client
     */
    protected Client createHttpClient(final FessConfig fessConfig, final String host) {
        final String[] hosts =