def list_domains(self):
        """Utility method to list all the domains in the jar."""
        domains = []
        for cookie in iter(self):
            if cookie.domain not in domains:
                domains.append(cookie.domain)
        return domains
Utility method to list all the domains in the jar.
stackoverflow/venv/lib/python3.6/site-packages/pip-19.0.3-py3.6.egg/pip/_vendor/requests/cookies.py