/// <summary>
 /// Initializes a new instance of the <see cref="LoggingMiddleware"/> class.
 /// </summary>
 /// <param name="next"></param>
 /// <param name="options"><see cref="LoggingMiddlewareOptions"/> to use to customize the current <see cref="LoggingMiddleware"/> behavior.</param>
 public LoggingMiddleware(RequestDelegate next, LoggingMiddlewareOptions options)
 {
     _next    = next ?? throw new ArgumentNullException(nameof(next));
     _options = options ?? new LoggingMiddlewareOptions();
 }
 public static void ConfigureLoggingMiddleware(this IApplicationBuilder app, LoggingMiddlewareOptions options)
 {
     app.UseMiddleware <LoggingMiddleware>(options);
 }