Rx\Observable::timer PHP Method

    public static function timer($dueTime, SchedulerInterface $scheduler = null)
    {
        return new TimerObservable($dueTime, $scheduler);
    }

 /**
  * @test
  */
 public function await_default_timeout()
 {
     $start = microtime(true);
     $observable = Observable::never()->takeUntil(Observable::timer(2000));
     $generator = \Rx\await($observable);
     foreach ($generator as $item) {
     }
     $totalTime = microtime(true) - $start;
     $this->assertEquals('2', round($totalTime));
 }