binding it in `init` might make the code here more readable. But, well, we're not in a performance-sensitive code here (this is happening once when we receive a message) so I wouldn't think too much about it :)

I would not do a more complex "cache it after the first time" code though: either cache it in `init` or don't cache it, we'll do something more fancy if this proves to be a problem. Do what you want amonst these solutions.