getWif method
Implementation
Future<String> getWif() async {
var buf = Buffer();
buf.addUint8(0x80);
buf.appendBytes(raw);
buf.addUint8(0x01);
var chksum = await Hash.sha256sha256(buf.bytes);
buf.appendBytes(chksum.sublist(0, 4));
return Base58.encode(buf.bytes);
}