code: public function findChanged(DateTimeImmutable $startTimestamp, DateTimeImmutable $endTimestamp)
      {
          $start = $startTimestamp->format(DATE_W3C);
          $end = $endTimestamp->format(DATE_W3C);
  
          return $this->client->getIterator('items', [
              'lang' => $this->languageHelper->getLanguagesQueryString(),
              'updatedBetween' => $start . ',' . $end,
              'with' => implode(',', self::$includes),
          ], function (array $elements) {
              $this->addAdditionalData($elements);
  
              return $elements;
          });
      }
docs: @param DateTimeImmutable $startTimestamp
  @param DateTimeImmutable $endTimestamp
  
  @return Iterator