The functions add_dependencies() and set_global() are convenience
methods that allow you to modify the global namespace while
the current file is running but then have it be cleaned up
by index.js when you're done.
(imported from commit f75b8a10c19f773a8d2d3a8fa4bc39b1679566fe)
This function returns the stream's actual name, if we can get it;
otherwise, it's the identity function.
(imported from commit 7a981adba9632d6c6eba54cb6514a9226d1e83e8)
