This very simple module provides two basic functions, one that always returns true (trueFunc) and one that always returns false (falseFunc).
By having only a single instance of these functions around, it's possible to do some nice optimizations.
Eg. css-select uses these functions to determine whether a selector won't match any elements
If that's the case, the DOM doesn't even need to be touched.
I'm trying to modularize css-select and most modules depend on these functions.
IMHO, having a separate module is the easiest solution to this problem.