[C#/TPL/.NET5] Task 클래스 : WhenAll 정적 메소드 사용시 예외 처리하기

using System;
using System.Threading.Tasks;

Task task1 = Task.Run(() => { throw new NotImplementedException();   });
Task task2 = Task.Run(() => { throw new InvalidOperationException(); });

Task task3 = Task.WhenAll(task1, task2);

try
{
    await task3;
}
catch
{
    AggregateException exception = task3.Exception;

    Console.WriteLine(exception.InnerExceptions.Count);
}