def generate_relay_config(self, environments: list) -> None:
        """Generate ld-relay.conf file.

        Given a list of environments of a project, this will generate a
        ``ld-relay.conf`` file in the current working directory. The conf file
        follows the specification that is documented in the main `ld-relay`_
        documentation.

        .. _ld-relay: https://github.com/launchdarkly/ld-relay#configuration-file-format

        :param environments: list of LaunchDarkly environments.
        """
        template = self.env.get_template('ld-relay.conf.jinja')

        with open('ld-relay.conf', 'w') as ld_relay_config:
            template = template.render(
                envs=environments
            )
            ld_relay_config.write(template)