I found the phrasing confusing. Mentionning that a class implements From and then using `into()` seems confusing. It looks like that you meant that it implements `Into`.
So I believe that a little more details may help show why this exercise is valid.
I would have considered clarifying that `into` does not need to specify that we use the implementation for `i16` thanks to type analysis, but I assume this would add too much text, and this can either be ignored by the reader for the time being, or guessed
