code: func doMount(mounter mount.Interface, devicePath, deviceMountPath, fsType string, options []string) error {
  	err := mounter.Mount(devicePath, deviceMountPath, fsType, options)
  	if err != nil {
  		klog.Errorf("Failed to mount the volume at %s, device: %s, error: %s", deviceMountPath, devicePath, err.Error())
  		return err
  	}
  	return nil
  }
docs: // Mounts the device at the given path.
  // It is expected that prepareForMount has been called before.