public void ToXmlStringWithSettingsReturnsCorrectResult(
            TestXmlWritable writable,
            IContentSerializer dummySerializer)
        {
            var settings = new XmlWriterSettings
            {
                OmitXmlDeclaration = true
            };

            var actual = writable.ToXmlString(dummySerializer, settings);

            var sb = new StringBuilder();
            using (var w = XmlWriter.Create(sb, settings))
            {
                writable.WriteTo(w);
                w.Flush();
            }
            var expected = XDocument.Parse(sb.ToString());
            Assert.Equal(
                expected,
                XDocument.Parse(actual),
                new XNodeEqualityComparer());
            Assert.False(
                actual.StartsWith("<?"),
                "XML declaration not expected due to XmlWriterSettings");
        }
        public void ToXmlStringReturnsCorrectResult(
            TestXmlWritable writable,
            IContentSerializer dummySerializer)
        {
            var actual = writable.ToXmlString(dummySerializer);

            var sb = new StringBuilder();
            using (var w = XmlWriter.Create(sb))
            {
                writable.WriteTo(w);
                w.Flush();
            }
            var expected = XDocument.Parse(sb.ToString());
            Assert.Equal(
                expected,
                XDocument.Parse(actual),
                new XNodeEqualityComparer());
        }