gtk_paint_expander question

[Dan Korostelev <dan ats energo ru>]

Hello, people.

I have a problem, when I try to draw expander it doesn't draw anything.
This is a simple program, illustrating how I'm trying to paint it.
What's wrong with it???? (It doesn't print any warnings in console)

---
#include <gtk/gtk.h>

int main(int argc, char *argv[]) {
        GtkWidget *win;

        gtk_init(&argc, &argv);
        win = gtk_window_new(GTK_WINDOW_TOPLEVEL);
        gtk_widget_show(win);

        gtk_paint_expander(win->style, win->window, GTK_STATE_NORMAL,
&win->allocation, gtk_tree_view_new(), NULL, 5, 5,
GTK_EXPANDER_COLLAPSED);

        gtk_main();
        return 0;
};
---

-- 
Dan Korostelev <dan ats energo ru>