code: func virtualMachineNames(vms []*object.VirtualMachine) string {
  	var s []string
  	for _, vm := range vms {
  		s = append(s, vm.Name())
  	}
  	return strings.Join(s, ",")
  }
docs: // virtualMachineNames is a helper method that returns all the names for a list
  // of virtual machines, comma separated.