public async Task GivenNullRequest_ReturnsNull()
                {
                    Microsoft.AspNetCore.Http.HttpRequest nullRequest = null;
                    // ReSharper disable once ExpressionIsAlwaysNull
                    var actual = await nullRequest.ToHttpRequestForVerification(_signature);

                    actual.Should().BeNull();
                }
                public void GivenNullSignature_ThrowsArgumentNullException()
                {
                    Func <Task> act = () => _httpRequest.ToHttpRequestForVerification(null);

                    act.Should().Throw <ArgumentNullException>();
                }