Saxon

.NET Framework 4.7, Saxon EE 9.9.1.4 When calling parse-xml-fragment:

` class Program { static Processor processor = new Processor(true);

    static string xslt = 
        @"<xsl:transform version='3.0' xmlns:xsl='http://www.w3.org/1999/XSL/Transform'>" +
        @" <xsl:template name='xsl:initial-template' > " +
        @"  <xsl:variable name='doc'>to je test</xsl:variable>" +
        @"  <xsl:sequence select='parse-xml-fragment($doc)'/>" +
        @" </xsl:template>" +
        @"</xsl:transform>";

    static void Main(string[] args)
    {
        XsltCompiler xsltCompiler = processor.NewXsltCompiler();
        xsltCompiler.XsltLanguageVersion = "3.0";
        XsltExecutable exec = xsltCompiler.Compile(new StringReader(xslt));
        Xslt30Transformer transf = exec.Load30();
        Serializer ser = processor.NewSerializer();
        StringWriter sw = new StringWriter();
        ser.SetOutputWriter(sw);
        transf.CallTemplate(null, ser);
        Console.WriteLine(sw.ToString());
     }

}`