public static function getInstance()
 {
     if (!isset(self::$_instance)) {
         self::$_instance = new self();
     }
     return self::$_instance;
 }
 public function __construct($template = NULL)
 {
     if (isset($template) && is_string($template)) {
         $this->_template = $template;
     }
     return parent::__construct();
 }