Avoid "self" referring to "window"; adjust comment placement

Issue #130 wasn't actually resolved. The problem is that `self` is not defined as `this` in this particular function, so if you use the function (though you don't currently use it internally), it will treat `self` as the [global "self"](https://developer.mozilla.org/en-US/docs/Web/API/Window.self) which is a reference to the `window` object.