urltools comes with an inbuilt
dataset of public suffixes, suffix_dataset.
This is used in suffix_extract to identify the top-level domain
within a particular domain name.
While updates to the dataset will be included in each new package release,
there's going to be a gap between changes to the suffixes list and changes to the package.
Accordingly, the package also includes suffix_refresh, which generates
and returns a fresh version of the dataset. This can then be passed through