code: func (pdev podDevices) containerDevices(podUID, contName, resource string) sets.String {
  	if _, podExists := pdev[podUID]; !podExists {
  		return nil
  	}
  	if _, contExists := pdev[podUID][contName]; !contExists {
  		return nil
  	}
  	devs, resourceExists := pdev[podUID][contName][resource]
  	if !resourceExists {
  		return nil
  	}
  	return devs.deviceIds
  }
docs: // Returns list of device Ids allocated to the given container for the given resource.
  // Returns nil if we don't have cached state for the given <podUID, contName, resource>.