code: func (fw *Framework) FederationCollectives() (collectives []string) {
  	var found []string
  
  	env := os.Getenv("CHORIA_FED_COLLECTIVE")
  
  	if env != "" {
  		found = strings.Split(env, ",")
  	}
  
  	if len(found) == 0 {
  		found = fw.Config.Choria.FederationCollectives
  	}
  
  	for _, collective := range found {
  		collectives = append(collectives, strings.TrimSpace(collective))
  	}
  
  	return
  }
docs: // FederationCollectives determines the known Federation Member
  // Collectives based on the CHORIA_FED_COLLECTIVE environment
  // variable or the choria.federation.collectives config item