initFromAsset method
Loads a model from an arbitrary Flutter asset path.
Example: await svc.initFromAsset('assets/models/russian-syntagrus.udpipe')
Returns immediately if assetPath is already loaded.
Implementation
Future<void> initFromAsset(String assetPath) {
if (_loadedModel == assetPath && isAvailable) return Future.value();
_initFuture = _loadFromAsset(assetPath);
return _initFuture;
}