code: protected function getIdsFromFilter($filter, $config)
      {
          $sorting = $this->extractSorting($config);
  
          return $this->getMetaModel()->getIdsFromFilter(
              $filter,
              $sorting[0],
              $config->getStart(),
              $config->getAmount(),
              strtoupper($sorting[1])
          );
      }
docs: Fetch the ids via the given filter.
  
  @param IFilter         $filter The filter.
  
  @param ConfigInterface $config The configuration to be applied.
  
  @return string[]