This library has this great property that it can be used not only for strings.
In fact it works for any Sequence of Hashable types.
This is great, because it can be used for lists of ints for example (which I needed), and all kinds of binary data (not necessarily with byte granularity).
(Of course case_insensitive flag doesn't make sense for those uses.)
This request is just to make this feature documented and supported.