While we are at it, why not going one step further and getting rid completely of the external dependency?
We basically only use it for writing \\ instead of \\\\. And this is used inconsistently in the tests, I would find it cleaner to not rely on this dependency, and be explicit. The only case that is worth is probably longEmailRegex in intersects_and_superset_of_complex_expression, but we can simply use longEmailRegex = longEmailRegex.replaceAll("\\\\", "\\\\\\\\"); for this one.

Thanks for handling this change and taking into account my comments 😄
Less dependency and more consistency 🚀
LGTM