const chart = Highcharts.chart('container', {
    credits: {
        enabled: false
    },
    xAxis: {
        categories: [
            'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep',
            'Oct', 'Nov', 'Dec'
        ]
    },
    series: [{
        data: [
            null, 71.5, 106.4, 129.2, null, 176.0, 135.6, 148.5, 216.4, 194.1,
            null, 54.4
        ]
    }, {
        data: [
            129.2, null, 176.0, 135.6, 0, 216.4, 194.1, null, 54.4, null, 71.5,
            106.4
        ],
        type: 'column',
        dataLabels: {
            enabled: true
        }
    }],
    navigation: {
        buttonOptions: {
            enabled: false
        }
    }
});

// the button handler
document.getElementById('button').addEventListener('click', () => {
    chart.exportChart();
});
