QUnit.test('Extremes are calculated from all series. #6209', function (assert) {
    var chart = Highcharts.chart('container', {
        chart: {
            type: 'heatmap'
        },
        colorAxis: {},
        series: [
            {
                data: [
                    [0, 1, 0],
                    [1, 2, 1]
                ]
            },
            {
                data: [
                    [3, 1, 100],
                    [4, 2, 600]
                ]
            }
        ]
    });

    assert.strictEqual(chart.colorAxis[0].max, 600, 'Max is 600');
    assert.strictEqual(chart.colorAxis[0].min, 0, 'Min is 0');
});
