Printing throws this exception:

Bad state: Future already completed
I/flutter ( 9568): #0 _AsyncCompleter.complete (dart:async/future_impl.dart:43:31)
I/flutter ( 9568): #1 PrinterBluetoothManager.writeBytes. (package:esc_pos_bluetooth/src/printer_bluetooth_manager.dart:117:23)
I/flutter ( 9568):
I/flutter ( 9568): #2 PrinterBluetoothManager.writeBytes. (package:esc_pos_bluetooth/src/printer_bluetooth_manager.dart)
I/flutter ( 9568): #3 _rootRunUnary (dart:async/zone.dart:1198:47)
I/flutter ( 9568): #4 _CustomZone.runUnary (dart:async/zone.dart:1100:19)
I/flutter ( 9568): #5 _CustomZone.runUnaryGuarded (dart:async/zone.dart:1005:7)
I/flutter ( 9568): #6 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:357:11)
I/flutter ( 9568): #7 _DelayedData.perform (dart:async/stream_impl.dart:611:14)
I/flutter ( 9568): #8 _StreamImplEvents.handleNext (dart:async/stream_impl.dart:730:11)
I/flutter ( 9568): #9 _PendingEvents.schedule. (dart:async/stream_impl.dart:687:7)
I/flutter ( 9568): #10 _rootRun (dart:async/zone.dart:1182:47)
I/flutter ( 9568): #11 _CustomZone.run (dart:async/zone.dart:1093:19)
I/flutter ( 9568): #12 _CustomZone.runGuarded (dart:async/zone.dart:997:7)