What are `e.render_args`, `e.update_args`, and `e.press_args`?

[whmountains]

I'm new to Piston graphics and I can't find any documentation for these particular functions I see being called from your main event loop. In my own app I just handle all the events in the main loop. It looks like you're using those function calls to avoid doing useless work, but I don't understand.

Can you point me to some information for what they do? Thanks a lot!