C#如何确保两个对象之间的自动双向链接

public class Linker
{
    private Object obj1;
    private Object obj2;

    public Object Obj1
    {
        get { return obj1; }
        set
        {
            if (obj1 != value)
            {
                if (obj1 != null)
                {
                    obj1 = null;
                }
                obj1 = value;
                obj1.Linker = this;
            }
        }
    }

    public Object Obj2
    {
        get { return obj2; }
        set
        {
            if (obj2 != value)
            {
                if (obj2 != null)
                {
                    obj2.Linker = null;
                }
                obj2 = value;
                obj2.Linker = this;
            }
        }
    }
}

public class Object
{
    private Linker linker;

    public Linker Linker
    {
        get { return linker; }
        set { linker = value; }
    }
}

Object obj1 = new Object();
Object obj2 = new Object();

Linker linker = new Linker();
linker.Obj1 = obj1;
linker.Obj2 = obj2;