    def make_homeserver(self, reactor, clock):
        config = self.default_config()
        config["redaction_retention_period"] = "30d"
        return self.setup_test_homeserver(
            resource_for_federation=Mock(), http_client=None, config=config
        )
A web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a Redirect. This simplifies phishing attacks.