signPoseidon method
Implementation
String signPoseidon(String privateKey, String msg) {
//if (lib == null) return "ERROR: The library is not initialized";
final prvKeyPtr = privateKey.toNativeUtf8();
final msgPtr = msg.toNativeUtf8();
final resultPtr = _signPoseidon(prvKeyPtr, msgPtr);
final String compressedSignature = resultPtr.toDartString();
//print("- Response string: $compressedSignature");
// Free the string pointer, as we already have
// an owned String to return
//print("- Freeing the native char*");
cstringFree(resultPtr);
return compressedSignature;
}