Pimcore\Model\Asset::getChildren PHP Method

    public function getChildren()
    {
        if ($this->childs === null) {
            $list = new Asset\Listing();
            $list->setCondition("parentId = ?", $this->getId());
            $list->setOrderKey("filename");
            $list->setOrder("asc");
            $this->childs = $list->load();
        }
        return $this->childs;
    }