code: public static function getString($language, $separator = ',')
      {
          $fileName = __DIR__ . '/stop-words/' . $language . '.txt';
          if (file_exists($fileName)) {
              return implode($separator, array_map('trim', file($fileName)));
          }
  
          return '';
      }
docs: Get stop-words list in string format - separated by defined separator
  
  @param string $language Language code (en, es, cs)
  @param string $separator word separator
  @return string