Further size reduction, you don't need the `this.` on the inline event listener, so it can be: `contentWindow.location.hash` and `contentDocument.body.childNodes` instead of `this.contentWindow.location.hash` or `this.contentDocument.body.childNodes`.
This will shave another 10 bytes off the snippet :D
Although location.hash defaults to the empty string '' when there is no hash, which gives a SyntaxError, so we still need the fallback selector to select none.
This will shave another 10 bytes off the snippet :D