handle.cs

public async Task Handle(int orderId, decimal amount)
{
    try
    {
        await _paymentGateway.Capture(orderId, amount);
    }
    catch (TimeoutException)
    {
        if (await _paymentGateway.MaybeCaptured(orderId) == false)
        {
            await RetryLater(orderId);
        }
    }
    catch (PaymentProviderException ex)
    {
        if (ex.Code == "DUPLICATE_REQUEST")
        {
            await CheckProviderState(orderId);
        }
        else if (ex.Code == "UNKNOWN")
        {
            await FlagForManualReview(orderId);
        }
        else
        {
            await CompensateInventory(orderId);
        }
    }
}