How to use the greynoise.util.CONFIG_FILE function in greynoise

def test_save_api_key(self, key_option):
        """Save API key to configuration file."""
        runner = CliRunner()
        api_key = ""
        expected_config = {
            "api_key": api_key,
            "api_server": DEFAULT_CONFIG["api_server"],
            "timeout": DEFAULT_CONFIG["timeout"],
        }
        expected_output = "Configuration saved to {!r}\n".format(CONFIG_FILE)

        with patch("greynoise.cli.subcommand.save_config") as save_config:
            result = runner.invoke(subcommand.setup, [key_option, api_key])
        assert result.exit_code == 0
        assert result.output == expected_output
        save_config.assert_called_with(expected_config)

def test_save_api_key_and_timeout(self, key_option, server_option, timeout_option):
        """Save API key and timeout to configuration file."""
        runner = CliRunner()
        api_key = ""
        api_server = ""
        timeout = 123456
        expected_config = {
            "api_key": api_key,
            "api_server": api_server,
            "timeout": timeout,
        }
        expected_output = "Configuration saved to {!r}\n".format(CONFIG_FILE)

        with patch("greynoise.cli.subcommand.save_config") as save_config:
            result = runner.invoke(
                subcommand.setup,
                [
                    key_option,
                    api_key,
                    server_option,
                    api_server,
                    timeout_option,
                    timeout,
                ],
            )
        assert result.exit_code == 0
        assert result.output == expected_output
        save_config.assert_called_with(expected_config)

def test_save_config_dir_created(self):
        """Configuration directory created if missing."""
        config = {
            "api_key": "",
            "api_server": "",
            "timeout": 123456,
        }

        with patch("greynoise.util.os") as os, patch("greynoise.util.open") as open_:
            os.path.isdir.return_value = False
            config_file = StringIO()
            open_().__enter__.return_value = config_file
            save_config(config)

        os.makedirs.assert_called_with(os.path.dirname(CONFIG_FILE))

def setup(api_key, timeout, api_server):
    """Configure API key."""
    config = {"api_key": api_key}

    if timeout is None:
        config["timeout"] = DEFAULT_CONFIG["timeout"]
    else:
        config["timeout"] = timeout

    if api_server is None:
        config["api_server"] = DEFAULT_CONFIG["api_server"]
    else:
        config["api_server"] = api_server

    save_config(config)
    click.echo("Configuration saved to {!r}".format(CONFIG_FILE))