code: protected function findControllerFiles()
      {
          $result = [];
          foreach ($this->controllerDirs as $dir) {
              $directoryIterator = new \RecursiveDirectoryIterator($dir);
              $iterator = new \RecursiveIteratorIterator($directoryIterator);
              $files = new \RegexIterator($iterator, '/\.php$/i', \RecursiveRegexIterator::GET_MATCH);
              foreach ($files as $k => $v) {
                  $result[$k] = filemtime($k);
              }
          }
  
          return $result;
      }
docs: Find all file in controller dir.