Add NACK processing
diff --git a/model/ccnx-pit-entry.cc b/model/ccnx-pit-entry.cc
index a4db50a..61b4fcc 100644
--- a/model/ccnx-pit-entry.cc
+++ b/model/ccnx-pit-entry.cc
@@ -49,6 +49,13 @@
   return ret.first;
 }
 
+void
+CcnxPitEntry::RemoveIncoming (Ptr<CcnxFace> face)
+{
+  m_incoming.erase (face);
+}
+
+
 CcnxPitEntryOutgoingFaceContainer::type::iterator
 CcnxPitEntry::AddOutgoing (Ptr<CcnxFace> face)
 {