CatalogBuilder::getProductParent

protected function getProductParent(int $entityId): ?int
	{
		if (!isset($this->parents[$entityId]))
		{
			$this->parents[$entityId] = false;
			$parents = CCatalogSku::getProductList([$entityId], $this->iblockId);
			if (!empty($parents) && isset($parents[$entityId]))
			{
				$this->parents[$entityId] = $parents[$entityId]['ID'];
			}
			unset($parents);
		}
		return (!empty($this->parents[$entityId]) ? $this->parents[$entityId] : null);
	}