delegateInput method
When asynchronous reading is not supported, an input for real reading will be cached in memory(web) or file(dart.io).
Implementation
@override
Future<HaveResourceImageInput> delegateInput() async {
final byteData = await this.byteData;
return HaveResourceImageInput(
innerInput: MemoryInput(byteData),
onRelease: () async {},
);
}