code: func filteredFinishedInvs(raw []byte, oldest time.Time) ([]*internal.FinishedInvocation, error) {
  	invs, err := unmarshalFinishedInvs(raw)
  	if err != nil {
  		return nil, err
  	}
  	filtered := make([]*internal.FinishedInvocation, 0, len(invs))
  	for _, inv := range invs {
  		if google.TimeFromProto(inv.Finished).After(oldest) {
  			filtered = append(filtered, inv)
  		}
  	}
  	return filtered, nil
  }
docs: // filteredFinishedInvocations unmarshals FinishedInvocationList and filters
  // it to keep only entries whose Finished timestamp is newer than 'oldest'.