code: func RadioButtonNewWithLabelFromWidget(radioGroupMember *RadioButton, label string) (*RadioButton, error) {
  	cstr := C.CString(label)
  	defer C.free(unsafe.Pointer(cstr))
  	var cradio *C.GtkRadioButton
  	if radioGroupMember != nil {
  		cradio = radioGroupMember.native()
  	}
  	c := C.gtk_radio_button_new_with_label_from_widget(cradio, (*C.gchar)(cstr))
  	if c == nil {
  		return nil, nilPtrErr
  	}
  	return wrapRadioButton(glib.Take(unsafe.Pointer(c))), nil
  }
docs: // RadioButtonNewWithLabelFromWidget is a wrapper around
  // gtk_radio_button_new_with_label_from_widget().