GtkAccelGroup Constructor
   
    Although not a part of the GTK object hierarchy, 
    GtkAccelGroup can be constructed in the same way
    as most GTK classes, i.e.
    
   
   
    In most cases, the newly-constructed GtkAccelGroup 
    would be used by all the menus belonging to that toplevel window, and
    should be added to it using 
    add_accel_group() .
   
   
    It is not always necessary to create an accelerator group in this way. 
    The GtkMenu method 
    ensure_uline_accel_group()  calls
    the GtkAccelGroup used internally by the menu for
    underline accelerators for the duration of the period that the menu is
    popped up.  If none is designated, a new accelerator group is created
    and used.