When Completable#isCompleted will be true if you give running Future to Completable#complete?

main.dart

import "dart:async";
void main() async {
  final job = Future.delayed(Duration(seconds: 2), () => print("ended"));
  final completer = Completer()..complete(job);
  print(completer.isCompleted);		// fal....true!?!?!?
  await job;
  print(completer.isCompleted);		// true, of course.
}