code: func (ac *accessController) Authorized(ctx context.Context, accessRecords ...auth.Access) (context.Context, error) {
  	req, err := dcontext.GetRequest(ctx)
  	if err != nil {
  		return nil, err
  	}
  
  	if req.Header.Get("Authorization") == "" {
  		challenge := challenge{
  			realm:   ac.realm,
  			service: ac.service,
  		}
  
  		if len(accessRecords) > 0 {
  			var scopes []string
  			for _, access := range accessRecords {
  				scopes = append(scopes, fmt.Sprintf("%s:%s:%s", access.Type, access.Resource.Name, access.Action))
  			}
  			challenge.scope = strings.Join(scopes, " ")
  		}
  
  		return nil, &challenge
  	}
  
  	ctx = auth.WithUser(ctx, auth.UserInfo{Name: "silly"})
  	ctx = dcontext.WithLogger(ctx, dcontext.GetLogger(ctx, auth.UserNameKey, auth.UserKey))
  
  	return ctx, nil
  
  }
docs: // Authorized simply checks for the existence of the authorization header,
  // responding with a bearer challenge if it doesn't exist.