public void WriteXmlToStream()
{
string xml = "<set><table1><col1>sample text</col1><col2/></table1><table2 attr='value'><col3>sample text 2</col3></table2></set>";
var ds = new DataSet();
ds.ReadXml(new StringReader(xml));
MemoryStream ms = new MemoryStream();
ds.WriteXml(ms);
MemoryStream ms2 = new MemoryStream(ms.ToArray());
StreamReader sr = new StreamReader(ms2, Encoding.UTF8);
string result = @"<set>
<table1>
<col1>sample text</col1>
<col2 />
</table1>
<table2 attr=""value"">
<col3>sample text 2</col3>
</table2>
</set>";
Assert.Equal(sr.ReadToEnd().Replace("\r\n", "\n"), result.Replace("\r\n", "\n"));
}