def METHOD_NAME(self, settingsWidget):
    settings = settingsWidget.getSettings()
    try:
        return self.concatenate(mainWindow().mdlOutline.rootItem, settings)
    except re.error as e:
        QMessageBox.warning(mainWindow().dialog, safeTranslate(qApp, "Export", "Error"),
                            safeTranslate(qApp, "Export", "Could not process regular expression: \n{}").format(str(e)))
        return ""