谁能帮我画一下下面的内存分配图示？自己不太清楚

class A
    {
        public A()
        {
            PrintFields();
        }
        public virtual void PrintFields() { }
    }
    class B : A
    {
        int x = 1;
        int y;
        public B()
        {
            y = -1;
        }
        public override void PrintFields()
        {
            Console.WriteLine("x={0},y={1}", x, y);
        }
    }

    class Program
    {       
        static void Main(string[] args)
        {
            B b = new B();
            //A a=new A();
            //a.PrintFields();
            b.PrintFields();
           
            Thread.Sleep(100000);
        }
    }