withoutGrid() not working

[akamasAT]

I want to get rid of the grid (the gray lines), the option withoutGrid() should handle this I think, but it has no effect on the Chart.

$lineChartModel = (new LineChartModel())->multiLine();
        $count->each(function ($value, $key) use(&$lineChartModel) {
            $lineChartModel->addSeriesPoint('Count', Carbon::parse($key)->format("F Y"), $value);
        });
        $lineChartModel->setSmoothCurve()
            ->setXAxisVisible(false)
            ->setYAxisVisible(false)
            ->withoutGrid()
            ->setColors(['#6eb33e'])
            ;

the Method is not documented - is it deprecated?