in src/main/java/org/apache/sling/scripting/xproc/cocoon/transform/SlingTransformer.java [113:126]
private TransformerHandler createTransformerHandler() throws Exception {
SAXTransformerFactory transformerFactory = (SAXTransformerFactory) TransformerFactory.newInstance();
TemplatesHandler templatesHandler = transformerFactory.newTemplatesHandler();
XMLReader xmlReader = XMLReaderFactory.createXMLReader();
xmlReader.setContentHandler(templatesHandler);
InputSource inputSource = new InputSource(getXsltSource());
xmlReader.parse(inputSource);
// Create transformer handler
final TransformerHandler handler = transformerFactory.newTransformerHandler(templatesHandler.getTemplates());
return handler;
}