public static void ObjectTree()
{
string json = @"{""MyIntMissing"":2, ""MyReference"":{""MyIntMissingChild"":3}}";
ClassWithReference obj = JsonSerializer.Parse <ClassWithReference>(json);
Assert.IsType <JsonElement>(obj.MyOverflow["MyIntMissing"]);
Assert.Equal(1, obj.MyOverflow.Count);
Assert.Equal(2, obj.MyOverflow["MyIntMissing"].GetInt32());
ClassWithExtensionProperty child = obj.MyReference;
Assert.IsType <JsonElement>(child.MyOverflow["MyIntMissingChild"]);
Assert.IsType <JsonElement>(child.MyOverflow["MyIntMissingChild"]);
Assert.Equal(1, child.MyOverflow.Count);
Assert.Equal(3, child.MyOverflow["MyIntMissingChild"].GetInt32());
}