code: func (s *Server) ReadFile(j *Job) ([]byte, error) {
  	data, err := httpGET(&s.auth, j.FileURL)
  	if err != nil {
  		return nil, fmt.Errorf("ReadFile: %v", err)
  	}
  	return data, nil
  }
docs: // ReadFile reads the raw data to be printed by the given job.