package main // domainGrouper groups by domain. // but it keeps the other fields. // for example: it returns pages as well, but you shouldn't use them. // exercise: write a function that erases superfluous data. func domainGrouper(r result) string { return r.domain } func pageGrouper(r result) string { return r.domain + r.page } // groupBy allocates map unnecessarily func noopGrouper(r result) string { // with something like: // return randomStrings() return "" }