[wendelinsky]

That is part of the es6-collections polyfill included as part of smap.js. If I understand correctly, it is for safety (for example you cannot override the value of "true").

[Twisol]

null, true, and false are all keywords. Isn't undefined the only one that can be redefined? (And then it's just equal to void 0.)

[emwendelin]

Yep, you're right. I forgot about that.