I had a 3rd party library throw an error, which I could traceroute back to the event listener hooks of `zone.js` in `meteorhacks:zones`. This line is failing: https://github.com/meteorhacks/zones/blob/master/assets/zone.js#L947 The reason is that `arguments[1]` is null, which is not checked. So I get the error message that property `_bound` cannot be found in undefined. Here's a screenshot of the failure situation: 