/// <summary>
/// Format the result according to the spec
/// </summary>
/// <returns>The formatted result</returns>
public override string ToString()
{
var sb = new StringBuilder();
sb.AppendLine($"Subtotal: {SubTotal.ToCustomFormatString()}");
foreach (var offer in Offers)
{
sb.AppendLine($"{offer.Description}: {offer.PriceDelta.ToCustomFormatString()}");
}
if (!Offers.Any())
{
sb.AppendLine("(No offers available)");
}
sb.AppendLine($"Total: {Total.ToCustomFormatString()}");
return(sb.ToString());
}