docs: Documentation update

Change-Id: I6f916eb822a59e980e8fb1134886c3431755119c
diff --git a/utils/trie/aggregate-stats-policy.hpp b/utils/trie/aggregate-stats-policy.hpp
index 3628cc6..4d2673b 100644
--- a/utils/trie/aggregate-stats-policy.hpp
+++ b/utils/trie/aggregate-stats-policy.hpp
@@ -27,6 +27,8 @@
 namespace ndn {
 namespace ndnSIM {
 
+/// @cond include_hidden
+
 /**
  * @brief Traits for policy that just keeps track of number of elements
  * It's doing a rather expensive job, but just in case it needs to be extended later
@@ -159,4 +161,6 @@
 } // ndn
 } // ns3
 
+/// @endcond
+
 #endif // AGGREGATE_STATS_POLICY_H_