// the provided spec.  See comments on NewWrapperMounter for more
	// context.
	NewWrapperUnmounter(volName string, spec Spec, podUID types.UID) (Unmounter, error)

	// Get mounter interface.
	GetMounter(pluginName string) mount.Interface

	// Returns the hostname of the host kubelet is running on
	GetHostName() string

	// Returns host IP or nil in the case of error.
	GetHostIP() (net.IP, error)