Use the object's prototype to store the changes

[ddeltree]

Consider not using any symbols, using the original and proposed properties directly, assuming these are not already present in the prototype.
Try to create class instances with these names as inherited fields or methods, and see if they collide or smth
I think they are stored 2 levels deep in the instance's prototypal inheritance chain, idk

[ddeltree]

Implemented by #18