Series index problem

HTML

<script src="http://code.highcharts.com/highcharts.js"></script>
<div id="container" style="height: 400px"></div>

JavaScript

$(function () {
		 (function(H) {
    H.Series.prototype.init = function(chart, options) {
      var series = this,
      	extend = H.extend,
        each = H.each,
        pick = H.pick,
        eventType,
        events,
        chartSeries = chart.series,
        NORMAL_STATE = '',
        win = window,
        doc = document,
        userAgent = (win.navigator && win.navigator.userAgent) || '',
				SVG_NS = 'http://www.w3.org/2000/svg',
        useCanVG = doc && !hasSVG && !isMS && !!doc.createElement('canvas').getContext,
        hasSVG = doc && doc.createElementNS && !!doc.createElementNS(SVG_NS, 'svg').createSVGRect,
        isMS = /(msie|trident|edge)/i.test(userAgent) && !isOpera,
        sortByIndex = function(a, b) {
          return pick(a.options.index, a._i) - pick(b.options.index, b._i);
        };

		function stableSort(arr, sortFunction) {
        var length = arr.length,
            sortValue,
            i;

        // Add index to each item
        for (i = 0; i < length; i++) {
            arr[i].safeI = i; // stable sort index
        }

        arr.sort(function (a, b) {
            sortValue = sortFunction(a, b);
            return sortValue === 0 ? a.safeI - b.safeI : sortValue;
        });

        // Remove index from items
        for (i = 0; i < length; i++) {
            delete arr[i].safeI; // stable sort index
        }
    }

      series.chart = chart;
      series.options = options = series.setOptions(options); // merge with plotOptions
      series.linkedSeries = [];

      // bind the axes
      series.bindAxes();

      // set some variables
      extend(series, {
        name: options.name,
        state: NORMAL_STATE,
        pointAttr: {},
        visible: options.visible !== false, // true by default
        selected: options.selected === true // false by default
      });

      // special
      if (useCanVG) {
        options.animation = false;
      }

      // register event listeners
      events = options.events;
  ...