public function get_capability($cap)
    {
        $cap      = strtoupper($cap);
        $sess_key = "STORAGE_$cap";

        if (!isset($_SESSION[$sess_key])) {
            if (!$this->check_connection()) {
                return false;
            }

            $_SESSION[$sess_key] = $this->conn->getCapability($cap);
        }

        return $_SESSION[$sess_key];
    }