Circular reference detection. Why GetHashCode is not valid in this case.

ObjectIdGeneratorPlayground.cs

var og = new ObjectIDGenerator();

var a = new { Name = "A" };
var b= new {Name = "A"};
var c = a;

var aid = og.GetId(a, out var firstTime);
var bid = og.GetId(b, out firstTime);
var cid = og.GetId(c, out firstTime);

var aHashCode = a.GetHashCode();
var bHashCode = b.GetHashCode();
var cHashCode = c.GetHashCode();

Console.WriteLine("Hello, World!");