using System;
using System.Threading.Tasks;

class Example
{
   static void Main()
   {
      int result = GetMultipleAsync(6).Result;
      Console.WriteLine($"The returned value is {result:N0}");
   }

   static async Task‹int› GetMultipleAsync(int secondsDelay)
   {
      Console.WriteLine("Executing GetMultipleAsync...");
      if (secondsDelay < 0 || secondsDelay > 5)
         throw new ArgumentOutOfRangeException("secondsDelay cannot exceed 5.");
         
      await Task.Delay(secondsDelay * 1000);
      return secondsDelay * new Random().Next(2,10);
   } 
}
// The example displays the following output:
//    Executing GetMultipleAsync...
//
//    Unhandled Exception: System.AggregateException: 
//         One or more errors occurred. (Specified argument was out of the range of valid values.
//    Parameter name: secondsDelay cannot exceed 5.) ---> 
//         System.ArgumentOutOfRangeException: Specified argument was 
//						out of the range of valid values.
//    Parameter name: secondsDelay cannot exceed 5.
//       at Example.‹GetMultiple›d__1.MoveNext() in Program.cs:line 17
//       --- End of inner exception stack trace ---
//       at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
//       at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
//       at Example.Main() in 
//C:\Users\ronpet\Documents\Visual Studio 2017\Projects\local-functions\async1\Program.cs:line 8