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

    public function cancelCalledOnChildrenSouldOnlyCancelWhenAllChildrenCancelled()
    {
        $adapter = $this->getPromiseTestAdapter($this->expectCallableNever());
        $child1 = $adapter->promise()->then()->then();
        $adapter->promise()->then();
        $child1->cancel();
    }