removed make_relation_node method from repository_node

source/core/object/object.cpp

@@ -75,4 +75,17 @@ size_t object::constraint_count() const {
 const std::list<class constraint>& object::constraints() const {
   return constraints_;
 }
-}
+
+std::ostream & operator<<(std::ostream &os, const object &obj) {
+  os << "Object " << obj.name_ << "\nAttributes:\n";
+  for (const auto &attr : obj.attributes_) {
+    os << " " << attr << "\n";
+  }
+  os << "Constraints:\n";
+  for (const auto &con : obj.constraints_) {
+    os << " " << con << "\n";
+  }
+  os << "\n";
+  return os;
+}
+}