code: func OptServerInternalClient(c InternalClient) ServerOption {
  	return func(s *Server) error {
  		s.executor = newExecutor(optExecutorInternalQueryClient(c))
  		s.defaultClient = c
  		s.cluster.InternalClient = c
  		return nil
  	}
  }
docs: // OptServerInternalClient is a functional option on Server
  // used to set the implementation of InternalClient.