code: func (n *NsenterMounter) doNsenterMount(source, target, fstype string, options []string) error {
  	glog.V(5).Infof("nsenter Mounting %s %s %s %v", source, target, fstype, options)
  	args := n.makeNsenterArgs(source, target, fstype, options)
  
  	glog.V(5).Infof("Mount command: %v %v", nsenterPath, args)
  	exec := exec.New()
  	outputBytes, err := exec.Command(nsenterPath, args...).CombinedOutput()
  	if len(outputBytes) != 0 {
  		glog.V(5).Infof("Output from mount command: %v", string(outputBytes))
  	}
  
  	return err
  }
docs: // doNsenterMount nsenters the host's mount namespace and performs the
  // requested mount.