code: func (f *Flags) Properties() *Properties {
  	contentType := types.ContentType(f.ContentType)
  	if contentType == "" {
  		contentType = f.Type.DefaultContentType()
  	}
  
  	p := &Properties{
  		LogStreamDescriptor: &logpb.LogStreamDescriptor{
  			Name:          string(f.Name),
  			ContentType:   string(contentType),
  			StreamType:    logpb.StreamType(f.Type),
  			Timestamp:     google.NewTimestamp(time.Time(f.Timestamp)),
  			BinaryFileExt: f.BinaryFileExtension,
  			Tags:          f.Tags,
  		},
  		Tee:      f.Tee,
  		Timeout:  time.Duration(f.Timeout),
  		Deadline: time.Duration(f.Deadline),
  	}
  	return p
  }
docs: // Properties converts the Flags to a standard Properties structure.
  //
  // If the values are not valid, this conversion will return an error.