code: func enforceExistingCgroup(cgroupManager CgroupManager, cName CgroupName, rl v1.ResourceList) error {
  	cgroupConfig := &CgroupConfig{
  		Name:               cName,
  		ResourceParameters: getCgroupConfig(rl),
  	}
  	if cgroupConfig.ResourceParameters == nil {
  		return fmt.Errorf("%q cgroup is not config properly", cgroupConfig.Name)
  	}
  	klog.V(4).Infof("Enforcing limits on cgroup %q with %d cpu shares, %d bytes of memory, and %d processes", cName, cgroupConfig.ResourceParameters.CpuShares, cgroupConfig.ResourceParameters.Memory, cgroupConfig.ResourceParameters.PidsLimit)
  	if !cgroupManager.Exists(cgroupConfig.Name) {
  		return fmt.Errorf("%q cgroup does not exist", cgroupConfig.Name)
  	}
  	if err := cgroupManager.Update(cgroupConfig); err != nil {
  		return err
  	}
  	return nil
  }
docs: // enforceExistingCgroup updates the limits `rl` on existing cgroup `cName` using `cgroupManager` interface.