Unhelpful error message in assertHasImplemented

[janhancic]

I got a topiarist error that some class hasn't implemented the protocol fully. It is impossible to tell which classes are involved from the error message.

And I can't check by travelling up the call stack, as the check is triggered from inside of a setTimeout in implement.

edit: it is possible to see the stack, if you are in Chrome and you enable "async stacks", but still ... :)