code: func NewGCSService(filename string) (*GCSService, error) {
  	ctx := context.Background()
  	client, err := storage.NewClient(ctx, option.WithServiceAccountFile(filename))
  	if err != nil {
  		return nil, err
  	}
  
  	service := &GCSService{
  		Client: client,
  	}
  
  	return service, nil
  }
docs: // NewGCSService returns a GCSSerivce object given a GCloud service account file path.