code: public function getData()
      {
          $cache = new ConfigCache($this->cacheFile, $this->debug);
          if (!$cache->isFresh()) {
              $routes = $this->wrappedGenerator->getData();
  
              $cache->write('<?php return '.var_export($routes, true).';');
          }
  
          return require $cache;
      }
docs: Get formatted route data for use by a URL generator
  
  @return array