How to use the zrender/src/core/util.clone function in zrender

ecModel.eachComponent({mainType: 'brush'}, function (brushModel, brushIndex) {

        var thisBrushSelected = {
            brushId: brushModel.id,
            brushIndex: brushIndex,
            brushName: brushModel.name,
            areas: zrUtil.clone(brushModel.areas),
            selected: []
        };
        // Every brush component exists in event params, convenient
        // for user to find by index.
        brushSelected.push(thisBrushSelected);

        var brushOption = brushModel.option;
        var brushLink = brushOption.brushLink;
        var linkedSeriesMap = [];
        var selectedDataIndexForLink = [];
        var rangeInfoBySeries = [];
        var hasBrushExists = 0;

        if (!brushIndex) { // Only the first throttle setting works.
            throttleType = brushOption.throttleType;
            throttleDelay = brushOption.throttleDelay;

* @private
   */
  var zr = this._zr = zrender.init(dom, {
    renderer: opts.renderer || defaultRenderer,
    devicePixelRatio: opts.devicePixelRatio,
    width: opts.width,
    height: opts.height
  });
  /**
   * Expect 60 fps.
   * @type {Function}
   * @private
   */

  this._throttledZrFlush = throttle(zrUtil.bind(zr.flush, zr), 17);
  var theme = zrUtil.clone(theme);
  theme && backwardCompat(theme, true);
  /**
   * @type {Object}
   * @private
   */

  this._theme = theme;
  /**
   * @type {Array.}
   * @private
   */

  this._chartsViews = [];
  /**
   * @type {Object.}
   * @private

function updateEl(el, dataIndex, elOption, animatableModel, data, isInit, isRoot) {
  var transitionProps = {};
  var elOptionStyle = elOption.style || {};
  elOption.shape && (transitionProps.shape = zrUtil.clone(elOption.shape));
  elOption.position && (transitionProps.position = elOption.position.slice());
  elOption.scale && (transitionProps.scale = elOption.scale.slice());
  elOption.origin && (transitionProps.origin = elOption.origin.slice());
  elOption.rotation && (transitionProps.rotation = elOption.rotation);

  if (el.type === 'image' && elOption.style) {
    var targetStyle = transitionProps.style = {};
    zrUtil.each(['x', 'y', 'width', 'height'], function (prop) {
      prepareStyleTransition(prop, targetStyle, elOptionStyle, el.style, isInit);
    });
  }

  if (el.type === 'text' && elOption.style) {
    var targetStyle = transitionProps.style = {};
    zrUtil.each(['x', 'y'], function (prop) {
      prepareStyleTransition(prop, targetStyle, elOptionStyle, el.style, isInit);

getMinMaxSpan: function () {
    return zrUtil.clone(this._minMaxSpan);
  },

function clipByPanel(controller, cover, data) {
  var panel = getPanelByCover(controller, cover);
  return panel && panel !== true ? panel.clipPath(data, controller._transform) : zrUtil.clone(data);
}

function updateCoverByMouse(controller, e, localCursorPoint, isEnd) {
  var creatingCover = controller._creatingCover;
  var panel = controller._creatingPanel;
  var thisBrushOption = controller._brushOption;
  var eventParams;

  controller._track.push(localCursorPoint.slice());

  if (shouldShowCover(controller) || creatingCover) {
    if (panel && !creatingCover) {
      thisBrushOption.brushMode === 'single' && clearCovers(controller);
      var brushOption = zrUtil.clone(thisBrushOption);
      brushOption.brushType = determineBrushType(brushOption.brushType, panel);
      brushOption.panelId = panel === true ? null : panel.panelId;
      creatingCover = controller._creatingCover = createCover(controller, brushOption);

      controller._covers.push(creatingCover);
    }

    if (creatingCover) {
      var coverRenderer = coverRenderers[determineBrushType(controller._brushType, panel)];
      var coverBrushOption = creatingCover.__brushOption;
      coverBrushOption.range = coverRenderer.getCreatingRange(clipByPanel(controller, creatingCover, controller._track));

      if (isEnd) {
        endCreating(controller, creatingCover);
        coverRenderer.updateCommon(controller, creatingCover);
      }

clone: function () {
        var Ctor = this.constructor;
        return new Ctor(zrUtil.clone(this.option));
    },

brushOptionList = zrUtil.map(brushOptionList, function (brushOption) {
            return zrUtil.merge(zrUtil.clone(DEFAULT_BRUSH_OPT), brushOption, true);
        });