add include directory
diff --git a/demo/chatdialog.cpp b/demo/chatdialog.cpp
index 9dac70b..0163df9 100644
--- a/demo/chatdialog.cpp
+++ b/demo/chatdialog.cpp
@@ -13,6 +13,11 @@
   m_nick = "Tester";
   m_chatroom = "Test";
 
+  DigestTreeScene *scene = new DigestTreeScene();
+
+  treeViewer->setScene(scene);
+  scene->plot();
+
   connect(lineEdit, SIGNAL(returnPressed()), this, SLOT(returnPressed()));
 }