public function getBackorderString():string
{
$backorder = '';
if ($this->cLagerBeachten === 'Y'
&& $this->fLagerbestand <= 0
&& $this->fZulauf > 0
&& $this->dZulaufDatum_de !== null
) {
$backorder = \sprintf(
Shop::Lang()->get('productInflowing', 'productDetails'),
$this->fZulauf,
$this->cEinheit,
$this->dZulaufDatum_de
);
}
return $backorder;
}