code: private static function loadFiles()
      {
          if (self::$_files === null) {
              self::$_files = [];
              if (isset($_FILES) && is_array($_FILES)) {
                  foreach ($_FILES as $class => $info) {
                      self::loadFilesRecursive($class, $info['name'], $info['tmp_name'], $info['type'], $info['size'], $info['error']);
                  }
              }
          }
  
          return self::$_files;
      }
docs: Creates UploadedFile instances from $_FILE.
  @return array the UploadedFile instances