priv_key.go
func (privKey PrivKeyEd25519) Equals(other PrivKey) bool {
	if otherEd, ok := other.(PrivKeyEd25519); ok {
		return subtle.ConstantTimeCompare(privKey[:], otherEd[:]) == 1
	} else {
		return false
	}
}
func (privKey PrivKeyEd25519) Equals(other PrivKey) bool {
	if otherEd, ok := other.(PrivKeyEd25519); ok {
		return subtle.ConstantTimeCompare(privKey[:], otherEd[:]) == 1
	} else {
		return false
	}
}
// Equals - you probably don't need to use this.
// Runs in constant time based on length of the keys.