code: func StorageVersionHash(group, version, kind string) string {
  	gvk := group + "/" + version + "/" + kind
  	if gvk == "" {
  		return ""
  	}
  	bytes := sha256.Sum256([]byte(gvk))
  	// Assuming there are N kinds in the cluster, and the hash is X-byte long,
  	// the chance of colliding hash P(N,X) approximates to 1-e^(-(N^2)/2^(8X+1)).
  	// P(10,000, 8) ~= 2.7*10^(-12), which is low enough.
  	// See https://en.wikipedia.org/wiki/Birthday_problem#Approximations.
  	return base64.StdEncoding.EncodeToString(
  		bytes[:8])
  }
docs: // StorageVersionHash calculates the storage version hash for a
  // <group/version/kind> tuple.
  // WARNING: this function is subject to change. Clients shouldn't depend on
  // this function.