start method
Implementation
Future<void> start() async {
await this.controller.start(
options: widget.options,
onInitialized: onInitialized,
onDocumentScanned: onDocumentScanned,
onFrameStatusChanged: onFrameStatusChanged,
onCurrentSideChanged: onCurrentSideChanged,
onCaptureCountDownChanged: onCaptureCountDownChanged,
);
}