Eep. I agree that that's a bad look. I also like the way that in one event handler in that file they check for the existence of stopImmediatePropagation before

Eep. I agree that that's a bad look. I also like the way that in one event handler in that file they check for the existence of stopImmediatePropagation before calling it and if it's not there they fall back `cancelBubble = true` to support old IE versions, but that in another spot they happily call stopImmediatePropagation() without any check. I'm not certain, but that certainly looks wrong; it seems like they'd've been better served by a polyfill.