Yuriy:
2. class may be defined with @__monitor attribute, in which case a __monitor variable will be added to it's beginning.
I suggest a name like "@monitor". The is no need for the underscores.
3. Subclass of such class may again be defined with @__monitor attar, in which case it will be simply ignored, as it already inherits __monitor from super.
A more tidy design could require the @monitor in all classes that inherit from a @monitor-annotated class. But this also looks a little overkill. So let's hear what other people think about this.
Bye, bearophile