anchor.diff:  /// Packed struct -- 36 bytes on 64-bit, 20 bytes on 32-bit
   class MCI_OPEN_PARMS extends Struct {
     @IntPtr()
  -  int dwCallback;
  -  @Uint32()
  -  int wDeviceID;
  -  Pointer<Utf16> lpstrDeviceType;
  -  Pointer<Utf16> lpstrElementName;
  -  Pointer<Utf16> lpstrAlias;
  +  external int dwCallback;
  +  @Uint32()
  +  external int wDeviceID;
  +  external Pointer<Utf16> lpstrDeviceType;
  +  external Pointer<Utf16> lpstrElementName;
  +  external Pointer<Utf16> lpstrAlias;
   
     factory MCI_OPEN_PARMS.allocate() => allocate<MCI_OPEN_PARMS>().ref
       ..dwCallback = 0
  
positive.code: /// {@category Struct}
  class MCI_STATUS_PARMS extends Struct {
    @IntPtr()
    int dwCallback;
    @IntPtr()
    int dwReturn;
    @Uint32()
    int dwItem;
    @Uint32()
    int dwTrack;
  
    factory MCI_STATUS_PARMS.allocate() => allocate<MCI_STATUS_PARMS>().ref
      ..dwCallback = 0
  
negative.code: /// {@category Struct}
  class MCI_PLAY_PARMS extends Struct {
    @IntPtr()
    external int dwCallback;
    @Uint32()
    external int dwFrom;
    @Uint32()
    external int dwTo;
  
    factory MCI_PLAY_PARMS.allocate() => allocate<MCI_PLAY_PARMS>().ref
      ..dwCallback = 0
  