[gtkada] toggle buttons in toolbar

[Maxim Reznik]

How can I build Gtk_Toggle_Button in Gtk_Toolbar?

When I run:

with Ada.Text_IO;
with Interfaces.C;

    declare
       Toggle : Gtk_Toggle_Button_Record;
       Button : Gtk_Toggle_Button;
       Widget : Gtk_Widget;
    begin
       Widget := Append_Element (ToolBar,
                                 Toolbar_Child_Togglebutton,
                                 Text => "Find",
                                 Icon => Image);

       Button := Gtk_Toggle_Button
         (Glib.Object.Unchecked_Cast (Widget, Toggle));
    end;

It fails in Unchecked_Cast while freeing Widget object.
Could you help?

Maxim