signIng method
Implementation
String signIng(Uint8List privateKey) {
var msg = getMessageToSign();
EcdaSignature result =
EcdaSignature.signForEth(dynamicToUint8List(msg), privateKey);
return "${(result.v + network.chainId * 2 + 8).toRadixString(16)}&${result.r.toStr()}&${result.s.toStr()}";
}