ParentFieldManager::getElementRelationIds

protected function getElementRelationIds(array $parentRelationElements): array
{
	$elementRelationIds = [];
	foreach ($parentRelationElements as $parentRelationsElement)
	{
		$parentEntityId = (int)$parentRelationsElement['SRC_ENTITY_ID'];
		$parentEntityTypeId = (int)$parentRelationsElement['SRC_ENTITY_TYPE_ID'];

		if (
			!isset($elementRelationIds[$parentEntityTypeId])
			|| !in_array($parentEntityId, $elementRelationIds[$parentEntityTypeId], true)
		)
		{
			$elementRelationIds[$parentEntityTypeId][] = $parentEntityId;
		}
	}
	return $elementRelationIds;
}