GtkSeparatorMenuItem a separator used in menus. The #GtkSeparatorMenuItem is a separator used to group items within a menu. It displays a horizontal line with a shadow to make it appear sunken into the interface. The #GtkSeparatorMenuItem-struct struct contains private data only, and should be accessed using the functions below. Creates a new #GtkSeparatorMenuItem. @Returns: a new #GtkSeparatorMenuItem.