You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: handshake.go
    path of file: ./repos/sliver/vendor/tailscale.com/control/controlbase
    
    the code of the file until where you have to start completion: // Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Cla
    
func newBLAKE2s() hash.Hash {
	h, err := blake2s.New256(nil)
	if err != nil {
		// Should never happen, errors only happen when using BLAKE2s
		// in MAC mode with a key.
		panic(err)
	}
	return h
}