Piwik\Widget\WidgetContainerConfig::getUniqueId PHP Method

    public function getUniqueId()
    {
        $parameters = $this->getParameters();
        unset($parameters['module']);
        unset($parameters['action']);
        unset($parameters['containerId']);
        return WidgetsList::getWidgetUniqueId($this->id, '', $parameters);
    }