Hiding the fact that a class is a DisplayObjectContainer

I have a class which will contain exactly one child, no more, no less, and other classes are not allowed to change that fact.

I could throw error messages every time a child is added or removed by overriding the default properties, but I don’t want the object to be treated as if it were a DisplayObjectContainer.

I want it to look like only a DisplayObject, yet I still want to add a child to it in private.

Is this possible?