public static function bookInvoice($invoiceGuid, $timestamp)
{
$res = self::getClient()->request('POST', 'https://api.dinero.dk/v1/' . self::$organizationId . '/invoices/' . $invoiceGuid . '/book', ['verify' => false, 'headers' => ['Authorization' => 'Bearer ' . self::$accessToken], 'json' => ['timestamp' => $timestamp]]);
return self::convertJson($res);
}