gtk/gtk_since_3_10.go
func (v *HeaderBar) SetSubtitle(subtitle string) {
	cstr := C.CString(subtitle)
	defer C.free(unsafe.Pointer(cstr))
	C.gtk_header_bar_set_subtitle(v.native(), (*C.gchar)(cstr))
}
func (v *HeaderBar) SetSubtitle(subtitle string) {
	cstr := C.CString(subtitle)
	defer C.free(unsafe.Pointer(cstr))
	C.gtk_header_bar_set_subtitle(v.native(), (*C.gchar)(cstr))
}
// SetSubtitle is a wrapper around gtk_header_bar_set_subtitle().