xslTransform.Transform to XslCompiledTransform.Transform

Hi I am clearing all warnings in my application, I used below code in my application

      DataSet dsBillItem = new DataSet();
      System.Xml.XPath.XPathNavigator xNav = xmlResponse.CreateNavigator();
      XslTransform xslTransform = new XslTransform();
      xslTransform.Load("test.xslt");
      XmlReader xmlReader = xslTransform.Transform(xNav, null);
      dsBillItem.ReadXml(xmlReader);

"XslTransform" showing warning as "This class has been deprecated. Please use System.Xml.Xsl.XslCompiledTransform instead. http://ift.tt/1qIVb8r".

If I change my code to "XslCompiledTransform", its throwing error on this line "XmlReader xmlReader = xslTransform.Transform(xNav, null);". Reason is this Transform method available only with void return type.

Please help me anyone on this, any code for xslt file to dataset conversion or any other way is available?