downloadFeature method
Starts the OS feature download. A failure to start is reported by
throwing — LocalAi.ensureReady() fails with it instead of waiting out
its timeout. The web host throws
LocalAiUserActivationRequiredException outside a user gesture.
Implementation
@override
Future<void> downloadFeature() async {
calls.add('downloadFeature');
final error = downloadFeatureError;
if (error != null) throw error;
}