ledger_secp256k1.go
func NewPrivKeyLedgerSecp256k1(path DerivationPath) (PrivKey, error) {
	var pk PrivKeyLedgerSecp256k1
	pk.Path = path
	// cache the pubkey for later use
	pubKey, err := pk.getPubKey()
	if err != nil {
		return nil, err
	}
	pk.CachedPubKey = pubKey
	return &pk, err
}
func NewPrivKeyLedgerSecp256k1(path DerivationPath) (PrivKey, error) {
	var pk PrivKeyLedgerSecp256k1
	pk.Path = path
	// cache the pubkey for later use
	pubKey, err := pk.getPubKey()
	if err != nil {
		return nil, err
	}
	pk.CachedPubKey = pubKey
	return &pk, err
}
// NewPrivKeyLedgerSecp256k1 will generate a new key and store the
// public key for later use.