main.cs

using System;
using System.Threading.Tasks;

public class Example
{
   
   public static async Task<int>  Main()
   {
       Console.WriteLine("Calling DoWorkAsync");
       var taskResult = DoWorkAsync(-5);
       Console.WriteLine("This hasn't thrown yet.");
       Console.WriteLine($"Is the task faulted: {taskResult.IsFaulted}");
       var returnCode = await taskResult;
       Console.WriteLine("After Await");
       return returnCode;
   }

   public static async Task<int> DoWorkAsync(int argument)
   {
       if (argument < 0)
        throw new ArgumentException(message: "Don't go negative", paramName: nameof(argument));

        await Task.Delay(argument);

        return argument;
   }
}