This func is only used by the kubelet and there's no need to pollute
client-go API with it.
Kubernetes-commit: 5c073abfe16fc0b9f62310b8276fc3b0c7043e60
Everything else it depends on was already there, and now we have a
somewhat consistent code chain.
Kubernetes-commit: 5649f9a578f4f130f61579d77d5609fbdaf82a1f