public static void Main()
{
DelReturnValue delReturnValue = new DelReturnValue(ReturnValue);
SayHello sayHello = new SayHello("test", delReturnValue);
Thread newThread = new Thread(new ThreadStart(sayHello.SayHelloMethod));
newThread.Start();
Thread.Sleep(1000);
Console.WriteLine("value is returned: " + _returnedValue);
}