get_balance (Xmms::Remote)

    /*
     * Get the balance level.
     *
     * This method raises an Xmms::Error exception if XMMS is not running.
     *
     * Note: as of XMMS 1.2.6 xmms_remote_get_balance() does not appear to
     * work correctly when XMMS is paused or stopped, so this function doesn't
     * either.
     *
     * Example:
     *   vol = remote.balance
     *
     */
    static VALUE xr_balance(VALUE self) {