public static function entity($name)
 {
     $p = self::DB_PATH . $name . ".db";
     if (!file_exists($p)) {
         if (!file_exists(dirname($p))) {
             mkdir(dirname($p), 0755, true);
         }
         $h = touch($p);
     }
     if (!empty(self::$entities[$name])) {
         $db = self::$entities[$name];
     } else {
         $db = new FileDB($p);
         $db->readData();
         self::$entities[$name] = $db;
     }
     return $db;
 }