public function create(array $args, array $payload) {
        $requiredFields = ['welitemSkuMetaId'];
        foreach ($requiredFields as $field) {
            if (empty($payload[$field])) {
                return Master::getErrorStore()->getErrorResponse(ErrorStore::REQUIRED_FIELDS_MISSING, [$field]);
            }
        }

        $groupId = (int)$args['groupId'];
        $welitemSkuMetaId = (int)$payload['welitemSkuMetaId'];
        $priceModifier = !empty($payload['priceModifier']) ? (float)$payload['priceModifier'] : 0;
        $itemLabel = !empty($payload['itemLabel']) ? (string)$payload['itemLabel'] : '';
        $itemQuantity = !empty($payload['itemQuantity']) ? (int)$payload['itemQuantity'] : 1;
        $itemQuantity = $itemQuantity < 1 ? 1 : $itemQuantity;
        $position = !empty($payload['position']) ? (int)$payload['position'] : 0;

        return API\GroupItem::createGroupItem(
            $groupId,
            $welitemSkuMetaId,
            $priceModifier,
            $itemLabel,
            $itemQuantity,
            $position
        );
    }