diff --git a/exercise1/node.h b/exercise1/node.h
index 89175ba..42b5b0d 100644
--- a/exercise1/node.h
+++ b/exercise1/node.h
@@ -12,7 +12,8 @@ class Node
 {
 
   public:
-    Node(const std::string &name = "");
+    Node(const std::string &name);
+    Node();
     virtual ~Node();
 
     std::string get_name() const;
@@ -22,7 +23,8 @@ class Node
     Node *get_child(int i) const;
     void add_child(Node *child);
 
-    void print(std::ostream &str = std::cout, uint32_t depth = 0) const;
+    void print(std::ostream& stream) const;
+    void print(std::ostream& stream, int level, std::set<const Node*>& set) const;
     static Node *create_complete_tree(uint32_t nr_child_nodes, uint32_t tree_depth);
     static void traverse_tree(const Node *node, std::function<void(const Node *, uint32_t)> predicate, bool recursive, uint32_t depth = 0);
 
@@ -36,6 +38,8 @@ class Node
     static void traverse_tree_iterative(const Node *node, std::function<void(const Node *, uint32_t)> predicate, uint32_t depth = 0);
 };
 
+std::string repeat(std::string value, int times);
+
 extern std::ostream &operator<<(std::ostream &os, const Node *node);
 
-#endif // NODE_H
\ No newline at end of file
+#endif // NODE_H