def METHOD_NAME(self):
    properties_widget = self._find_widget()
    self._set_link(properties_widget)
    self.assertEqual(properties_widget._ui.condition_script_edit.toPlainText(), "exit(23)")
    QApplication.processEvents()
    properties_widget.unset_link()
    self.assertEqual(properties_widget._ui.condition_script_edit.toPlainText(), "exit(23)")