diff --git a/include/ui.h b/include/ui.h
index 24c79e4..6b4dd5c 100644
--- a/include/ui.h
+++ b/include/ui.h
@@ -118,3 +118,5 @@ void ui_send_internal_notification  (const char *message);
 void ui_close_internal_notification (void);
 void ui_toggle_sidebar              ();
 
+void tree_c_printing_test(void);
+
diff --git a/src/main.c b/src/main.c
index da36c5e..b5723f7 100644
--- a/src/main.c
+++ b/src/main.c
@@ -32,6 +32,9 @@
 
 int main(int argc, char **argv)
 {
+
+    tree_c_printing_test();
+
     g_autoptr(GemGraphClientApplication) app = NULL;
     int res;
 
diff --git a/src/ui/tree.c b/src/ui/tree.c
index 4636c08..5dae879 100644
--- a/src/ui/tree.c
+++ b/src/ui/tree.c
@@ -28,4 +28,10 @@
 #include "../../include/base.h"
 #include "../../include/ui.h"
 
+void tree_c_printing_test(void)
+{
+    printf("tree_c_printing_test() \
+------------------------------------------------------\n\
+trying : https://en.wikibooks.org/wiki/GTK\%\2B_By_Example/Tree_View/Tree_Models\n");
+}