public function removedNodesCannotBeRetrievedAnymore()
{
$rootNode = $this->context->getRootNode();
$rootNode->createNode('quux');
$rootNode->getNode('quux')->remove();
$this->assertNull($rootNode->getNode('quux'));
$barNode = $rootNode->createNode('bar');
$barNode->remove();
$this->persistenceManager->persistAll();
$this->assertNull($rootNode->getNode('bar'));
$rootNode->createNode('baz');
$this->persistenceManager->persistAll();
$rootNode->getNode('baz')->remove();
$bazNode = $rootNode->getNode('baz');
// workaround for PHPUnit trying to "render" the result *if* not NULL
$bazNodeResult = $bazNode === null ? null : 'instance-of-' . get_class($bazNode);
$this->assertNull($bazNodeResult);
}