code: func (p Path) Split() (bucket string, filename string) {
  	v, ok := trimPrefix(string(p), "gs://")
  	if ok {
  		// Has a "gs://" prefix, trim that to get the bucket.
  		sidx := strings.IndexRune(v, '/')
  		if sidx <= 0 {
  			// Only a Google Storage bucket name.
  			bucket = v
  			return
  		}
  
  		bucket = v[:sidx]
  		v = v[sidx+1:]
  	}
  	filename = v
  	return
  }
docs: // Split returns the bucket and filename components of the Path.
  //
  // If a bucket is not defined (doesn't begin with "gs://"), the remainder will
  // be considered to be the filename component. If a filename is not defined,
  // an empty string will be returned.