public async Task RejectsRequest(
                HttpContext httpContext,
                int expectedHttpStatusCode)
            {
                var instance = new RequireForwardedForHeaderMiddleware(Next);
                await instance.InvokeAsync(httpContext)
                .ConfigureAwait(false);

                Assert.Equal(expectedHttpStatusCode,
#pragma warning disable CA1062 // Validate arguments of public methods
                             httpContext.Response.StatusCode);
#pragma warning restore CA1062 // Validate arguments of public methods
            }
            public void ReturnsInstance()
            {
                var instance = new RequireForwardedForHeaderMiddleware(Next);

                Assert.NotNull(instance);
            }