code: func SystemOrDefault(client *govmomi.Client, name string, dc *object.Datacenter) (*object.HostSystem, error) {
  	finder := find.NewFinder(client.Client, false)
  	finder.SetDatacenter(dc)
  
  	ctx, cancel := context.WithTimeout(context.Background(), provider.DefaultAPITimeout)
  	defer cancel()
  	t := client.ServiceContent.About.ApiType
  	switch t {
  	case "HostAgent":
  		return finder.DefaultHostSystem(ctx)
  	case "VirtualCenter":
  		if name != "" {
  			return finder.HostSystem(ctx, name)
  		}
  		return finder.DefaultHostSystem(ctx)
  	}
  	return nil, fmt.Errorf("unsupported ApiType: %s", t)
  }
docs: // SystemOrDefault returns a HostSystem from a specific host name and
  // datacenter. If the user is connecting over ESXi, the default host system is
  // used.