public void FromAcceptLanguageHeader(string header, string expectedCulture)
    {
        var acceptLanguage = new RequestHeaders(new HeaderDictionary {
            ["accept-language"] = header
        }).AcceptLanguage;

        var returnedCulture = CultureUtil.FromAcceptLanguageHeader(acceptLanguage, supportedCultures, new CultureInfo("de-AT"));

        returnedCulture.Should().Be(new CultureInfo(expectedCulture));
    }