System.Xml.Xsl.XsltOld.Processor.GetNavigator C# (CSharp) Method

        internal XPathNavigator GetNavigator(Uri ruri) {
            XPathNavigator result = null;
            if (documentCache != null) {
                result = documentCache[ruri] as XPathNavigator;
                if (result != null) {
                    return result.Clone();
                }
            }
            else {
                documentCache = new Hashtable();
            }

            Object input = resolver.GetEntity(ruri, null, null);
            if (input is Stream) {
                XmlTextReaderImpl tr  = new XmlTextReaderImpl(ruri.ToString(), (Stream) input); {
                    tr.XmlResolver = this.resolver;
                }
                // reader is closed by Compiler.LoadDocument()
                result = ((IXPathNavigable)Compiler.LoadDocument(tr)).CreateNavigator();
            }
            else if (input is XPathNavigator){
                result = (XPathNavigator) input;
            }
            else {
                throw XsltException.Create(Res.Xslt_CantResolve, ruri.ToString());
            }
            documentCache[ruri] = result.Clone();
            return result;
        }