code: func (s *Scheduler) activeFormationCount(appID string) int {
  	activeReleases := make(map[string]struct{})
  	for _, job := range s.jobs {
  		if job.IsRunning() && job.IsInApp(appID) {
  			activeReleases[job.Formation.Release.ID] = struct{}{}
  		}
  	}
  	return len(activeReleases)
  }
docs: // activeFormationCount returns the number of formations which have running
  // jobs for the given app