code: func (cc *Controller) loadConfig(source checkpoint.RemoteConfigSource) (*kubeletconfig.KubeletConfiguration, string, error) {
  	// load KubeletConfiguration from checkpoint
  	kc, err := cc.checkpointStore.Load(source)
  	if err != nil {
  		return nil, status.LoadError, err
  	}
  	// apply any required transformations to the KubeletConfiguration
  	if cc.transform != nil {
  		if err := cc.transform(kc); err != nil {
  			return nil, status.InternalError, err
  		}
  	}
  	// validate the result
  	if err := validation.ValidateKubeletConfiguration(kc); err != nil {
  		return nil, status.ValidateError, err
  	}
  	return kc, "", nil
  }
docs: // loadConfig loads Kubelet config from a checkpoint
  // It returns the loaded configuration or a clean failure reason (for status reporting) and an error.