Rx\Functional\React\PromiseToObservableTest::to_observable_cancels_on_dispose PHP Method

    public function to_observable_cancels_on_dispose()
    {
        $canceled = false;
        $deferred = new Deferred(function () use(&$canceled) {
            $canceled = true;
        });
        $o = Promise::toObservable($deferred->promise());
        $this->scheduler->schedule(function () use($deferred) {
            $deferred->resolve(1);
        }, 300);
        $results = $this->scheduler->startWithDispose(function () use($o) {
            // adding the merge causes 2 subscriptions to test that the count
            // of cancels works correctly through disposal
            return $o->merge($o);
        }, 250);
        $this->assertMessages([], $results->getMessages());
        $this->assertTrue($canceled);
    }