SmartDoorLock_G3/ConsoleApp3/Program.cs

using System.Collections.Concurrent;

namespace ConsoleApp3
{
    internal class Program
    {
        static void Main(string[] args)
        {
            var tests=new ConcurrentQueue<MyClass>();
            tests.TryDequeue(out var result);
            if (result != null)
            {
                Console.WriteLine("not null");
            }
            else { Console.WriteLine("result is null"); }
        }
        class MyClass
        {

        }
    }
}