def METHOD_NAME(self):
    actual_country_count = len(list_supported_countries(include_aliases=False))
    readme_country_count = int(
        re.findall(r"We currently support (\d+) country codes.", self.readme_content)[0]
    )
    self.assertEqual(
        readme_country_count,
        actual_country_count,
        "README.rst supported countries statement is out of date: "
        f"'We currently support {readme_country_count} countries'. "
        f"Actual supported countries count: {actual_country_count}",
    )