code: func NewClient(t string, conf map[string]string) (Client, error) {
  	f, ok := BuiltinClients[t]
  	if !ok {
  		return nil, fmt.Errorf("unknown remote client type: %s", t)
  	}
  
  	return f(conf)
  }
docs: // NewClient returns a new Client with the given type and configuration.
  // The client is looked up in the BuiltinClients variable.