Don't use it in your own objects!
Just in case somebody wonders what kind of names efun308 is it isn't an efun name at all, but rather a makeshift because there is none yet; hopefully, with the existance of the efun (and maybe others), the issue of their naming will become a bit more interesting than what command shell was used on a room-filling dinosaur of a computer some decades ago.
Hyp proposes to christen efun308() 'set_environment()'.