public void GetSitemapTest_ShouldThrowInvalidKeyException()
        {
            var invalidButterClient = new ButterCMSClient("I'm not a valid key");

            Assert.Throws <InvalidKeyException>(() => invalidButterClient.GetSitemap());
        }
        public void GetSitemapTest_ShouldReturnXMLDocument()
        {
            var xml = butterClient.GetSitemap();

            Assert.IsNotNull(xml);
        }