code: @Override
    public <T> ConnectionFactory<T> getConnectionFactory(final Identifier connFactoryId) {
      final ConnectionFactory<T> connFactory = connFactoryMap.get(connFactoryId.toString());
      if (connFactory == null) {
        throw new RuntimeException("Cannot find ConnectionFactory of " + connFactoryId + ".");
      }
      return connFactory;
    }
docs: Gets a ConnectionFactory.
  @param connFactoryId the identifier of the ConnectionFactory