React\Promise\PromiseTest\CancelTestTrait::cancelShouldAlwaysTriggerCancellerWhenCalledOnRootPromise PHP Method

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