code: func (n *Network) OrgsForOrderers(ordererNames []string) []*Organization {
  	orgsByName := map[string]*Organization{}
  	for _, name := range ordererNames {
  		orgName := n.Orderer(name).Organization
  		orgsByName[orgName] = n.Organization(orgName)
  	}
  	orgs := []*Organization{}
  	for _, org := range orgsByName {
  		orgs = append(orgs, org)
  	}
  	return orgs
  }
docs: // OrgsForOrderers returns all Organization instances that own at least one of
  // the named orderers.