React\Promise\PromiseTest\CancelTestTrait::cancelShouldTriggerCancellerOnlyOnceWhenCancellingMultipleTimes PHP Метод

    public function cancelShouldTriggerCancellerOnlyOnceWhenCancellingMultipleTimes()
    {
        $adapter = $this->getPromiseTestAdapter($this->expectCallableOnce());
        $adapter->promise()->cancel();
        $adapter->promise()->cancel();
    }