text: $(function () {
      QUnit.test('Sub-millisecond tooltip', function (assert) {
          var chart = new Highcharts.Chart({
              chart: {
                  renderTo: 'container'
              },
              title: {
                  text: 'Tooltip shows only year when xAxis.closestPointRange < 1 msec',
                  x: -20 //center
              },
              xAxis: {
                  type: 'datetime'
              },
              series: [{
                  data: [
                      [1432548947841.300, 7.0],
                      [1432548947841.700, 6.9]
                  ]
              }]
          });
  
  
          assert.equal(
              Highcharts.Tooltip.prototype.getXDateFormat.call(chart.tooltip, chart.series[0].points[0], chart.options.tooltip, chart.xAxis[0]),
              '%A, %b %e, %H:%M:%S.%L',
              'Milliseconds are preserved in tooltip'
          );
  
      });
  
  });