tests: add FreshnessPeriod where MustBeFresh is used

refs #4913

Change-Id: Idf7e85b46ea9530678b51bf1f472ecfcfca5773f
diff --git a/tests/test-common.hpp b/tests/test-common.hpp
index 71c1d08..9a648a0 100644
--- a/tests/test-common.hpp
+++ b/tests/test-common.hpp
@@ -29,17 +29,18 @@
 #include <boost/asio.hpp>
 #include <boost/test/unit_test.hpp>
 
-#include <ndn-cxx/util/scheduler.hpp>
-#include <ndn-cxx/security/key-chain.hpp>
-#include <ndn-cxx/util/time-unit-test-clock.hpp>
-
-#include <ndn-cxx/security/signature-sha256-with-rsa.hpp>
 #include <ndn-cxx/face.hpp>
+#include <ndn-cxx/security/key-chain.hpp>
+#include <ndn-cxx/security/signature-sha256-with-rsa.hpp>
 #include <ndn-cxx/util/dummy-client-face.hpp>
+#include <ndn-cxx/util/scheduler.hpp>
+#include <ndn-cxx/util/time-unit-test-clock.hpp>
 
 namespace nlsr {
 namespace test {
 
+using namespace ndn::time_literals;
+
 ndn::Data&
 signData(ndn::Data& data);
 
@@ -154,6 +155,7 @@
     }
 
     auto data = make_shared<ndn::Data>(name);
+    data->setFreshnessPeriod(1_s);
     data->setFinalBlock(name[-1]);
     data->setContent(std::forward<ContentArgs>(contentArgs)...);
     this->signDatasetReply(*data);