getPrivateKey method
Get a private key for a specific change and address index, throwing an exception if it's a public-only key.
Implementation
IPrivateKey getPrivateKey(int changeIndex, int addrIndex) {
if (isPublicOnly) {
throw const MessageException(
'Public-only deterministic keys have no private half');
}
return _derivePrivateKey(changeIndex, addrIndex);
}