magickGetImage method
Gets the image at the current image index.
Don't forget to call destroyMagickWand on the returned MagickWand when done.
This method runs inside an isolate different from the main isolate.
Implementation
Future<MagickWand?> magickGetImage() async => MagickWand._fromAddress(
await _magickCompute(
_magickGetImage,
_wandPtr.address,
),
);