diff --git a/tests/test-common.hpp b/tests/test-common.hpp
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+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2016,  Regents of the University of California,
+ *                           Arizona Board of Regents,
+ *                           Colorado State University,
+ *                           University Pierre & Marie Curie, Sorbonne University,
+ *                           Washington University in St. Louis,
+ *                           Beijing Institute of Technology,
+ *                           The University of Memphis.
+ *
+ * This file is part of NDNS (Named Data Networking Domain Name Service) and is
+ * based on the code written as part of NFD (Named Data Networking Daemon).
+ * See AUTHORS.md for complete list of NDNS authors and contributors.
+ *
+ * NDNS is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ *
+ * NDNS 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
+ * NDNS, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef NDNS_TESTS_TEST_COMMON_HPP
+#define NDNS_TESTS_TEST_COMMON_HPP
+
+#include "logger.hpp"
+
+#include <ndn-cxx/name.hpp>
+#include <ndn-cxx/data.hpp>
+#include <ndn-cxx/interest.hpp>
+#include <ndn-cxx/link.hpp>
+#include <ndn-cxx/lp/nack.hpp>
+#include <ndn-cxx/util/dummy-client-face.hpp>
+#include <ndn-cxx/security/key-chain.hpp>
+
+#include <boost/version.hpp>
+#include <boost/asio.hpp>
+#include <boost/filesystem.hpp>
+
+#include <fstream>
+
+#include "boost-test.hpp"
+#include "unit-test-common-fixtures.hpp"
+#include "identity-management-fixture.hpp"
+
+namespace ndn {
+namespace ndns {
+namespace tests {
+
+/** \brief create an Interest
+ *  \param name Interest name
+ *  \param nonce if non-zero, set Nonce to this value
+ *               (useful for creating Nack with same Nonce)
+ */
+shared_ptr<Interest>
+makeInterest(const Name& name, uint32_t nonce = 0);
+
+/** \brief create a Data with fake signature
+ *  \note Data may be modified afterwards without losing the fake signature.
+ *        If a real signature is desired, sign again with KeyChain.
+ */
+shared_ptr<Data>
+makeData(const Name& name);
+
+/** \brief add a fake signature to Data
+ */
+Data&
+signData(Data& data);
+
+/** \brief add a fake signature to Data
+ */
+inline shared_ptr<Data>
+signData(shared_ptr<Data> data)
+{
+  signData(*data);
+  return data;
+}
+
+/** \brief create a Link object with fake signature
+ *  \note Link may be modified afterwards without losing the fake signature.
+ *        If a real signature is desired, sign again with KeyChain.
+ */
+shared_ptr<Link>
+makeLink(const Name& name, std::initializer_list<std::pair<uint32_t, Name>> delegations);
+
+/** \brief create a Nack
+ *  \param name Interest name
+ *  \param nonce Interest nonce
+ *  \param reason Nack reason
+ */
+lp::Nack
+makeNack(const Name& name, uint32_t nonce, lp::NackReason reason);
+
+/** \brief replace a name component
+ *  \param[inout] name name
+ *  \param index name component index
+ *  \param a arguments to name::Component constructor
+ */
+template<typename...A>
+void
+setNameComponent(Name& name, ssize_t index, const A& ...a)
+{
+  Name name2 = name.getPrefix(index);
+  name2.append(name::Component(a...));
+  name2.append(name.getSubName(name2.size()));
+  name = name2;
+}
+
+template<typename Packet, typename...A>
+void
+setNameComponent(Packet& packet, ssize_t index, const A& ...a)
+{
+  Name name = packet.getName();
+  setNameComponent(name, index, a...);
+  packet.setName(name);
+}
+
+} // namespace tests
+} // namespace ndns
+} // namespace ndn
+
+#endif // NFD_TESTS_TEST_COMMON_HPP