examples: Adding example for the experimental support of PIT aggregate stats
diff --git a/model/pit/ndn-pit-impl.h b/model/pit/ndn-pit-impl.h
index 024054a..26e3a6b 100644
--- a/model/pit/ndn-pit-impl.h
+++ b/model/pit/ndn-pit-impl.h
@@ -88,7 +88,7 @@
 
   virtual Ptr<Entry>
   Find (const Name &prefix);
-  
+
   virtual Ptr<Entry>
   Create (Ptr<const Interest> header);
 
@@ -113,6 +113,9 @@
   const typename super::policy_container &
   GetPolicy () const { return super::getPolicy (); }
 
+  typename super::policy_container &
+  GetPolicy () { return super::getPolicy (); }
+
 protected:
   void RescheduleCleaning ();
   void CleanExpired ();
@@ -137,7 +140,7 @@
   Ptr<ForwardingStrategy> m_forwardingStrategy;
 
   static LogComponent g_log; ///< @brief Logging variable
-  
+
   // indexes
   typedef
   boost::intrusive::multiset<entry,