code: func GetCgroupDriverDocker(execer utilsexec.Interface) (string, error) {
  	driver, err := callDockerInfo(execer)
  	if err != nil {
  		return "", err
  	}
  	return strings.TrimSuffix(driver, "\n"), nil
  }
docs: // TODO: add support for detecting the cgroup driver for CRI other than
  // Docker. Currently only Docker driver detection is supported:
  // Discussion:
  //     https://github.com/kubernetes/kubeadm/issues/844
  // GetCgroupDriverDocker runs 'docker info -f "{{.CgroupDriver}}"' to obtain the docker cgroup driver