def user_is_blacklisted(self, user):
        for blacklisted_user in self.blacklist.get('users', []):
            if re.match(blacklisted_user, user):
                return True
        return False
Takes a username as a string and returns a boolean. True indicates that
dataset/ETHPy150Open saltstack/salt/salt/acl/__init__.py/PublisherACL.user_is_blacklisted