Highcharts.chart('container', {

    chart: {
        type: 'column'
    },

    title: {
        text: 'Round legend symbols'
    },

    xAxis: {
        categories: ['Jan', 'Feb', 'Mar', 'Apr']
    },

    legend: {
        symbolHeight: 12,
        symbolWidth: 12,
        symbolRadius: 6
    },

    series: [{
        data: [1, 3, 2, 4]
    }, {
        data: [6, 4, 5, 3]
    }, {
        data: [2, 7, 6, 5]
    }]

});
