code: func ExtractResourceValueByContainerName(fs *v1.ResourceFieldSelector, pod *v1.Pod, containerName string) (string, error) {
  	container, err := findContainerInPod(pod, containerName)
  	if err != nil {
  		return "", err
  	}
  	return ExtractContainerResourceValue(fs, container)
  }
docs: // ExtractResourceValueByContainerName extracts the value of a resource
  // by providing container name