-void gtk_chart_set_datas(GtkChart *chart, GtkTreeModel *model, guint column, gchar *title);
-void gtk_chart_set_dualdatas(GtkChart *chart, GtkTreeModel *model, guint column1, guint column2, gchar *title);
+void gtk_chart_set_datas(GtkChart *chart, GtkTreeModel *model, guint column, gchar *title, gchar *subtitle);
+void gtk_chart_set_dualdatas(GtkChart *chart, GtkTreeModel *model, guint column1, guint column2, gchar *title, gchar *subtitle);