public function close()
 {
     return XPM3_FUNC::close($this->_conn);
 }
 public static function pquit($conn = null)
 {
     try {
         if (!($conn && is_resource($conn))) {
             throw new Exception('invalid resource connection', 0);
         } else {
             if (!fwrite($conn, 'QUIT' . self::CRLF)) {
                 throw new Exception('0 -> can not write', 1);
             } else {
                 if (!self::result($conn, $response, '+OK')) {
                     throw new Exception('1 -> ' . implode(', ', $response), 1);
                 } else {
                     XPM3_FUNC::close($conn);
                     return true;
                 }
             }
         }
     } catch (Exception $e) {
         return self::exception_handler($e, self::disconnect($conn));
     }
 }