downloadModel method
Downloads the model required to process the specified language. If model has been previously downloaded it returns 'exists'.
Else returns success or failure depending on whether the download completes or not.
To see available models visit https://developers.google.com/ml-kit/vision/digital-ink-recognition/base-models
Implementation
Future<String> downloadModel(String modelTag) async {
final result = await Vision.channel.invokeMethod('vision#manageInkModels',
<String, dynamic>{'task': 'download', 'modelTag': modelTag});
return result.toString();
}