(async () => {

    // Load the dataset
    const data = await fetch(
        'https://www.highcharts.com/samples/data/usdeur.json'
    ).then(response => response.json());

    const year = new Date(data[data.length - 1][0]).getFullYear(); // Get
    // year of last data point

    // Create the chart
    Highcharts.stockChart('container', {

        rangeSelector: {
            selected: 4
        },

        title: {
            text: 'USD to EUR exchange rate'
        },

        yAxis: {
            title: {
                text: 'Exchange rate'
            }
        },

        plotOptions: {
            flags: {
                accessibility: {
                    exposeAsGroupOnly: true,
                    description: 'Flagged events.'
                }
            }
        },

        series: [{
            name: 'USD to EUR',
            data: data,
            id: 'dataseries',
            tooltip: {
                valueDecimals: 4
            }
        }, {
            type: 'flags',
            data: [{
                x: Date.UTC(year, 1, 22),
                title: 'A',
                text: 'Shape: "squarepin"'
            }, {
                x: Date.UTC(year, 3, 28),
                title: 'A',
                text: 'Shape: "squarepin"'
            }],
            onSeries: 'dataseries',
            shape: 'squarepin',
            borderRadius: 3,
            width: 16
        }, {
            type: 'flags',
            data: [{
                x: Date.UTC(year, 2, 1),
                title: 'B',
                text: 'Shape: "circlepin"'
            }, {
                x: Date.UTC(year, 3, 1),
                title: 'B',
                text: 'Shape: "circlepin"'
            }],
            shape: 'circlepin',
            width: 16
        }, {
            type: 'flags',
            data: [{
                x: Date.UTC(year, 2, 10),
                title: 'C',
                text: 'Shape: "flag"'
            }, {
                x: Date.UTC(year, 3, 11),
                title: 'C',
                text: 'Shape: "flag"'
            }],
            color: Highcharts.getOptions().colors[0], // same as onSeries
            fillColor: Highcharts.getOptions().colors[0],
            onSeries: 'dataseries',
            width: 16,
            style: { // text style
                color: 'white'
            },
            states: {
                hover: {
                    fillColor: '#395C84' // darker
                }
            }
        }]
    });
})();