This example request the current stock quote price for Apple:
	public class AppleStock : IPropertyFunction
	{
		public string Execute(TemplateContext context, IServiceLocator services)
		{
			var stocks = services.GetInstance<IStockQuoteService>();
			var quote = stocks.FindBySymbol("AAPL");
			return quote.Price.ToString();
		}
	}
The code for this example is located in
src/Dovetail.PropertyExtensionExamples/Functions/AppleStock.cs.