Code review comment for lp:~andreas-pokorny/mir/fix-1531517

> LGTM. For my changes ill just be hard coding an uint8_t[20] for the mac, sooo
> this wont cause me any issues. Which will just give me a operator= copy/move
> for the mac anyway soo no fancy changes needed on my end here.
>
> Sooo really depends on whos branch lands first :), should be a simple conflict
> (if any)
>
> One things:
> +#include <unordered_set>
> + std::unordered_set<size_t> sent_indices;
>
> Doesnt seem to be used?

yes removed that