code: func (v *TextView) GetWindow(win TextWindowType) *gdk.Window {
  	c := C.gtk_text_view_get_window(v.native(), C.GtkTextWindowType(win))
  	if c == nil {
  		return nil
  	}
  	return &gdk.Window{glib.Take(unsafe.Pointer(c))}
  }
docs: // GetWindow is a wrapper around gtk_text_view_get_window().