code: func (daemon *Daemon) ContainerCopy(name string, res string) (io.ReadCloser, error) {
  	container, err := daemon.GetContainer(name)
  	if err != nil {
  		return nil, err
  	}
  
  	// Make sure an online file-system operation is permitted.
  	if err := daemon.isOnlineFSOperationPermitted(container); err != nil {
  		return nil, errdefs.System(err)
  	}
  
  	data, err := daemon.containerCopy(container, res)
  	if err == nil {
  		return data, nil
  	}
  
  	if os.IsNotExist(err) {
  		return nil, containerFileNotFound{res, name}
  	}
  	return nil, errdefs.System(err)
  }
docs: // ContainerCopy performs a deprecated operation of archiving the resource at
  // the specified path in the container identified by the given name.