code: func (bs *Bootstrap) GetViewerURL(paths ...types.StreamPath) (string, error) {
  	if bs.Project == "" {
  		return "", errors.New("no project is configured")
  	}
  	if bs.CoordinatorHost == "" {
  		return "", errors.New("no coordinator host is configured")
  	}
  	return viewer.GetURL(bs.CoordinatorHost, bs.Project, paths...), nil
  }
docs: // GetViewerURL returns a log stream viewer URL to the aggregate set of supplied
  // stream paths.
  //
  // If both the Project and CoordinatorHost values are not populated, an error
  // will be returned.