error with timeout and emitWithAck

[mfOryx]

Hi,
I have this on flutter:

_socket.timeout(5000).emitWithAck(event, data, ack: (dynamic result) { if (kDebugMode) { print('ack $result'); } if (result != null) { if (kDebugMode) { print('from server $result'); return result; } } else { if (kDebugMode) { print("Null"); } return null; } });

without the timeout, everything works fine.
With the timeout, I receive this error:
Unhandled Exception: type 'Null' is not a subtype of type 'bool'

[jumperchen]

any reproducible example? or please test with the latest 3.0.0-beta.4 version to give it a try.