try to get all ooxml-lite classes loaded for xslf

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1893361 13f79535-47bb-0310-9956-ffa450edef68

poi-integration/src/test/java/org/apache/poi/stress/XSLFFileHandler.java

@@ -41,6 +41,7 @@ class XSLFFileHandler extends SlideShowHandler {
             assertNotNull(slideInner.getSlideReferences());
 
             new POIXMLDocumentHandler().handlePOIXMLDocument(slide);
+            POIXMLDocumentHandler.cursorRecursive(slide.getCTPresentation());
 
             handleSlideShow(slide);
         } catch (POIXMLException e) {