Repo function to get sibling $category objects but not the $category itself

repogetsiblings

  // This is what I currently have, but of course $category is also found
public function findSiblings($category = NULL) {
	$query = $this->createQuery();
	
	$query->matching(
		$query->logicalAnd(
			$query->equals('hidden', 0),
			$query->equals('published', 1),
			$query->equals('parent', $category->getParent())
		)
	);
	
	$query->setOrderings(
		array('title' => \TYPO3\Flow\Persistence\QueryInterface::ORDER_ASCENDING)
	);
	
	return $query->execute();
}

	// I tried this (persistence_object_identifier maybe the wrong columns name in this example - I can't rememeber exactly what it is, but in my real code it's whatever you see in phpmayadmin as the objects unique identifier)
...
	$query->matching(
		$query->logicalAnd(
			$query->equals('hidden', 0),
			$query->equals('published', 1),
			$query->equals('parent', $category->getParent())
			$query->logicalNot(
				$query->equals('persistence_object_identifier', $category),
			)
		)
	);
...