code: func (n *Mounter) doNsenterMount(source, target, fstype string, options []string) error {
  	klog.V(5).Infof("nsenter mount %s %s %s %v", source, target, fstype, options)
  	cmd, args := n.makeNsenterArgs(source, target, fstype, options)
  	outputBytes, err := n.ne.Exec(cmd, args).CombinedOutput()
  	if len(outputBytes) != 0 {
  		klog.V(5).Infof("Output of mounting %s to %s: %v", source, target, string(outputBytes))
  	}
  	return err
  }
docs: // doNsenterMount nsenters the host's mount namespace and performs the
  // requested mount.