code: func (v *Dialog) GetHeaderBar() *Widget {
  	c := C.gtk_dialog_get_header_bar(v.native())
  	if c == nil {
  		return nil
  	}
  	return wrapWidget(glib.Take(unsafe.Pointer(c)))
  }
docs: /*
   * Dialog
   */
  // GetHeaderBar is a wrapper around gtk_dialog_get_header_bar().