How to use the @microsoft/signalr.NullLogger.instance function in @microsoft/signalr

return new Promise((resolve, reject) => {
            const httpClient = new DefaultHttpClient(NullLogger.instance);
            httpClient.get(url).then((response) => {
                if (response.statusCode >= 200 && response.statusCode < 300) {
                    resolve(response.content as string);
                } else {
                    reject(new Error(response.statusText));
                }
            });
        });
    }