using System.Threading.Tasks;
public static void Main()
Console.WriteLine("Success");
Console.WriteLine("Failed to call external service: " + ex);
static void CallService()
CallServiceAndDisplayResult(1);
CallServiceAndDisplayResult(0);
CallServiceAndDisplayResult(-1);
static async void CallServiceAndDisplayResult(int integer)
var result = await ExternalService.GetStringValue(integer);
Console.WriteLine(result);
static class ExternalService
public static async Task<string> GetStringValue(int integer)
await Task.Delay(TimeSpan.FromSeconds(1));
throw new NotSupportedException("Negative integers not supported.");
return integer.ToString();