Piwik\Plugins\VisitFrequency\Reports\Get::addSparklineColumns PHP Method

    private function addSparklineColumns(Sparklines $view)
    {
        $view->config->addSparklineMetric(array('nb_visits_returning'));
        $view->config->addSparklineMetric(array('avg_time_on_site_returning'));
        $view->config->addSparklineMetric(array('nb_actions_per_visit_returning'));
        $view->config->addSparklineMetric(array('bounce_rate_returning'));
        $view->config->addSparklineMetric(array('nb_actions_returning'));
    }