anchor.diff:  // Enumerates device interfaces that support Bluetooth LE
   
   import 'dart:ffi';
  -import 'dart:typed_data';
   
   import 'package:ffi/ffi.dart';
   import 'package:win32/win32.dart';
  
positive.code: // GATT Security and Other Flag-related Facilities
  // -----------------------------------------------------------------------------
  
  void printServicesByDevice(String path) {
    final pathPtr = TEXT(path);
  
    final hDevice = CreateFile(pathPtr.cast(), 0,
        FILE_SHARE_READ | FILE_SHARE_WRITE, nullptr, OPEN_EXISTING, 0, NULL);
    if (hDevice == INVALID_HANDLE_VALUE) {
      final error = GetLastError();
      print('CreateFile - Get Device Handle error: $error');
      throw WindowsException(error);
    }
    try {
      int hr;
      using((Arena arena) {
        final bufferCountPtr = arena<USHORT>();
        hr = BluetoothGATTGetServices(
            hDevice, 0, nullptr, bufferCountPtr, BLUETOOTH_GATT_FLAG_NONE);
        if (hr != HRESULT_FROM_WIN32(ERROR_MORE_DATA)) {
          print('BluetoothGATTGetServices - Get Buffer Count error: $hr');
          throw WindowsException(hr);
        }
  
        final serviceBufferPtr = arena<BTH_LE_GATT_SERVICE>(bufferCountPtr.value);
        final numServicesPtr = arena<USHORT>();
  
        hr = BluetoothGATTGetServices(hDevice, bufferCountPtr.value,
            serviceBufferPtr, numServicesPtr, BLUETOOTH_GATT_FLAG_NONE);
  
        if (hr != S_OK) {
          print('BluetoothGATTGetServices - Get Service Buffer error: $hr');
          throw WindowsException(hr);
        }
        for (var i = 0; i < numServicesPtr.value; i++) {
          print(
              'BluetoothGATTService - ${serviceBufferPtr[i].ServiceUuid.LongUuid}');
        }
      });
    } finally {
      CloseHandle(hDevice);
      free(pathPtr);
    }
  }
  
negative.code:   });
  
    for (final path in devicePaths) {
      final pathPtr = TEXT(path);
      final hDevice = CreateFile(pathPtr.cast(), 0,
          FILE_SHARE_READ | FILE_SHARE_WRITE, nullptr, OPEN_EXISTING, 0, NULL);
      if (hDevice == INVALID_HANDLE_VALUE) {
        final error = GetLastError();
        print('CreateFile - Get Device Handle error: $error');
        throw WindowsException(error);
      }
  
      try {
        print('BLUETOOTHLE_DEVICE - $path');
        printServicesByDevice(hDevice);
      } finally {
        CloseHandle(hDevice);
        free(pathPtr);
      }
    }
  }
  
  