code: func (a *API) FeedsLookup(ctx context.Context, query *feed.Query) ([]byte, error) {
  	_, err := a.feed.Lookup(ctx, query)
  	if err != nil {
  		return nil, err
  	}
  	var data []byte
  	_, data, err = a.feed.GetContent(&query.Feed)
  	if err != nil {
  		return nil, err
  	}
  	return data, nil
  }
docs: // FeedsLookup finds Swarm feeds updates at specific points in time, or the latest update