private string RenderHtml(StatementData data)
{
var result = $"<h1>{data.Customer}</h1>\n";
result += "<table>\n";
result += "<tr><th>play</th><th>seats</th><th>cost</th>\n";
foreach (var perf in data.Performances)
{
// print line for this order
result += $"<tr><td>{perf.Play.Name}</td><td>{perf.Audience}</td><td>{FormatUtilities.Usd(perf.Amount)}</td>\n";
}
result += "</table>\n";
result += $"<p>Amount owed is <em>{FormatUtilities.Usd(data.TotalAmount)}</em></p>\n";
result += $"<p>You earned <em>{data.TotalVolumeCredits}</em> credits</p>\n";
return(result);
}