Yes, good point. I put this into a separate commit before making any
changes to the code, which means that it diffs cleanly within the
branch, but the diff between branches won't be very useful. I'll push
changes reverting this commit (as well as the commit moving the summary
function to the stats module).

However, bringing back the name conflict between the sample module and
the function results in not being able to import the sample module
directly (meaning that only the functions from sample.py imported into
__init__.py can be tested), so I think this it is worth renaming
sample.py back to sampling.py at some point.