onRequest method
Called when the request is about to be sent.
Implementation
@override
void onRequest(
RequestOptions options,
RequestInterceptorHandler handler,
) async {
if (appVersion != null) {
options.headers['App-Version'] = appVersion;
}
if (appName != null) {
options.headers['App-Name'] = appName;
}
if (device != null) {
options.headers['Device'] = device;
}
handler.next(options);
}