code: func (j Jobs) WithFormationAndType(f *Formation, typ string) sortJobs {
  	jobs := make(sortJobs, 0, len(j))
  	for _, job := range j {
  		if job.Formation == f && job.Type == typ {
  			jobs = append(jobs, job)
  		}
  	}
  	jobs.Sort()
  	return jobs
  }
docs: // WithFormationAndType returns a list of jobs which belong to the given
  // formation and have the given type, ordered with the most recently started
  // job first