unsubscribe method
Implementation
Future<void> unsubscribe({List<UnsubscribeStreams>? streams}) async {
var payload = {"request": "unsubscribe", "streams": streams?.map((e) => e.toMap()..removeWhere((key, value) => value == null)).toList()}
..removeWhere((key, value) => value == null);
await this.send(data: payload);
}