create static method
Creates a RequestTracker to be configured for manually tracking an HTTP
request to track it manually, with a non-null url
and after having
called Instrumentation.start.
Method might throw Exception.
Implementation
static Future<RequestTracker> create(String url) async {
try {
final tracker = RequestTracker._();
final args = {"id": tracker.id, "url": url};
await channel.invokeMethod<void>('getRequestTrackerWithUrl', args);
return tracker;
} on PlatformException catch (e) {
throw Exception(e.details);
}
}