Stats tree seems to work properly, including pruning of "empty" leaves
diff --git a/model/ccnx-pit-entry.h b/model/ccnx-pit-entry.h
index beda5bb..1ccb6b4 100644
--- a/model/ccnx-pit-entry.h
+++ b/model/ccnx-pit-entry.h
@@ -84,7 +84,7 @@
  *
  * All set-methods are virtual, in case index rearrangement is necessary in the derived classes
  */
-struct CcnxPitEntry : SimpleRefCount<CcnxPitEntry>
+class CcnxPitEntry : public SimpleRefCount<CcnxPitEntry>
 {
 public:
   typedef std::set< CcnxPitEntryIncomingFace > in_container; ///< @brief incoming faces container type