code: func (s *LogStream) DescriptorProto() (*logpb.LogStreamDescriptor, error) {
  	desc := logpb.LogStreamDescriptor{}
  	if err := proto.Unmarshal(s.Descriptor, &desc); err != nil {
  		return nil, err
  	}
  	return &desc, nil
  }
docs: // DescriptorProto unmarshals a LogStreamDescriptor from the stream's Descriptor
  // field. It will return an error if the unmarshalling fails.