Another set of refactoring
diff --git a/helper/ccnb-parser/syntax-tree/ext.h b/helper/ccnb-parser/syntax-tree/ext.h
new file mode 100644
index 0000000..072405c
--- /dev/null
+++ b/helper/ccnb-parser/syntax-tree/ext.h
@@ -0,0 +1,61 @@
+/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2011 University of California, Los Angeles
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+
+#ifndef _CCNB_PARSER_EXT_H_
+#define _CCNB_PARSER_EXT_H_
+
+#include "block.h"
+
+namespace ns3 {
+namespace ndn {
+namespace CcnbParser {
+
+/**
+ * \ingroup ccnx-ccnb
+ * \brief Class to represent EXT ccnb-encoded node
+ *
+ * \see http://www.ccnx.org/releases/latest/doc/technical/BinaryEncoding.html
+ */
+class Ext : public Block
+{
+public:
+ /**
+ * \brief Constructor that actually parsed ccnb-encoded DTAG block
+ *
+ * \param start buffer iterator pointing to the next byte past EXT block
+ * \param extSubtype extension type (extracted from the value field)
+ *
+ * \see http://www.ccnx.org/releases/latest/doc/technical/BinaryEncoding.html
+ */
+ Ext (Buffer::Iterator &start, uint32_t extSubtype);
+
+ virtual void accept( VoidNoArguVisitor &v ) { v.visit( *this ); }
+ virtual void accept( VoidVisitor &v, boost::any param ) { v.visit( *this, param ); }
+ virtual boost::any accept( NoArguVisitor &v ) { return v.visit( *this ); }
+ virtual boost::any accept( Visitor &v, boost::any param ) { return v.visit( *this, param ); }
+
+ uint64_t m_extSubtype; ///< \brief Extension type
+};
+
+}
+}
+}
+
+#endif // _CCNB_PARSER_EXT_H_