protected function setCategoryField()
    {
        $sCategoryID = array_get($this->arImportData, 'category_id');
        if ($sCategoryID === null) {
            return;
        }

        //Find category by external ID
        $obCategory = Category::getByExternalID($sCategoryID)->first();
        if (empty($obCategory)) {
            $this->arImportData['category_id'] = null;
        } else {
            $this->arImportData['category_id'] = $obCategory->id;
        }
    }