Add datastore support for YANG actions

Change-Id: I15b96f70ce89b7bbe3ac0fefb7b018374eeabd84
diff --git a/tests/pretty_printers.hpp b/tests/pretty_printers.hpp
index 65e28a6..6864443 100644
--- a/tests/pretty_printers.hpp
+++ b/tests/pretty_printers.hpp
@@ -42,7 +42,7 @@
 {
     s << "DatastoreAccess::Tree {\n";
     for (const auto& [xpath, value] : tree) {
-        s << "    {" << xpath << ", " << leafDataToString(value) << "}\n";
+        s << "    {" << xpath << ", " << leafDataToString(value) << "},\n";
     }
     s << "}\n";
     return s;