code: func FindById(id string) (*Job, error) {
  	job := &Job{}
  	t := newTransaction()
  	t.scanJobById(id, job)
  	if err := t.exec(); err != nil {
  		switch e := err.(type) {
  		case ErrorJobNotFound:
  			// If the job was not found, add the id to the error
  			// so that the caller can get a more useful error message.
  			e.id = id
  			return nil, e
  		default:
  			return nil, err
  		}
  	}
  	return job, nil
  }
docs: // FindById returns the job with the given id or an error if the job cannot be found
  // (in which case the error will have type ErrorJobNotFound) or there was a problem
  // connecting to the database.