code: func NewOrdererClientFromEnv() (*OrdererClient, error) {
  	address, override, clientConfig, err := configFromEnv("orderer")
  	if err != nil {
  		return nil, errors.WithMessage(err, "failed to load config for OrdererClient")
  	}
  	gClient, err := comm.NewGRPCClient(clientConfig)
  	if err != nil {
  		return nil, errors.WithMessage(err, "failed to create OrdererClient from config")
  	}
  	oClient := &OrdererClient{
  		commonClient: commonClient{
  			GRPCClient: gClient,
  			address:    address,
  			sn:         override}}
  	return oClient, nil
  }
docs: // NewOrdererClientFromEnv creates an instance of an OrdererClient from the
  // global Viper instance