CloneSlice is analogous to [slices.Clone] except that is uses `copy` instead of `append`.

CompactSlice will return either the input slice, or a copy of it with a cap == len(slice).

DrainBuffer removes any values from the buffered channel.

TODO: is this in the standard somewhere yet?.

TODO: is this in the standard somewhere yet?.

Closer wraps a close function to satisfy [io.Closer].