anychart.onDocumentReady(function () {
var chart = anychart.line();
var series = chart.jumpLine([
{x: 'January', value: 5},
{x: 'February', value: 6},
series.stroke(function () {
return anychart.color.setThickness(anychart.color.darken(this.sourceColor), 3);
chart.title('Set stroke parameter as a function');
chart.container('container');