code: private function getFilename(string $name): string
      {
          //Runtime cache
          return sprintf(
              "%s/%s.%s",
              $this->directory,
              strtolower(str_replace(['/', '\\'], '-', $name)),
              self::EXTENSION
          );
      }
docs: Get extension to use for runtime data or configuration cache.
  
  @param string $name Runtime data file name (without extension).
  
  @return string