Piwik\Plugins\CustomVariables\Reports\GetCustomVariables::isReportContainsUnsetVisitsColumns PHP Method

    public function isReportContainsUnsetVisitsColumns(DataTable $report)
    {
        $visits = $report->getColumn('nb_visits');
        $isVisitsMetricsSometimesUnset = in_array(false, $visits);
        return $isVisitsMetricsSometimesUnset;
    }