foreach ($items as $item) {
          $this->metadataProvider->convertDate($item, $component->getName());
          $stream->writeCsv($this->metadataProvider->getRowData($item, $fields, $options));
    }

foreach ($items as $item) {
$item['base_grand_total'] = $item['base_currency_code'].$item['base_grand_total'];
            $srItem['grand_total'] = $item['order_currency_code'].$item['grand_total'];
            $item['subtotal'] = $item['base_currency_code'].$item['subtotal'];
            $item['shipping_and_handling'] = $item['base_currency_code'].$item['shipping_and_handling'];
                $this->metadataProvider->convertDate($item, $component->getName());
                $stream->writeCsv($this->metadataProvider->getRowData($item, $fields, $options));
            }