ledger_secp256k1.go
func (pk PrivKeyLedgerSecp256k1) Equals(other PrivKey) bool {
	if ledger, ok := other.(*PrivKeyLedgerSecp256k1); ok {
		return pk.CachedPubKey.Equals(ledger.CachedPubKey)
	}
	return false
}
func (pk PrivKeyLedgerSecp256k1) Equals(other PrivKey) bool {
	if ledger, ok := other.(*PrivKeyLedgerSecp256k1); ok {
		return pk.CachedPubKey.Equals(ledger.CachedPubKey)
	}
	return false
}
// Equals fulfils PrivKey Interface - makes sure both keys refer to the
// same