message: Enable change hover style when hovering.
diff: @@ -279,17 +279,18 @@ Painter.prototype = {
  },
  addHover: function (el, hoverStyle) {
  - if (el.__hoverMir) {
  - return;
  - }
  - var elMirror = new el.constructor({
  + var elMirror = el.__hoverMir;
  + if (!elMirror) {
  + elMirror = new el.constructor({
  style: el.style,
  shape: el.shape
  });
  elMirror.__from = el;
  el.__hoverMir = elMirror;
  - elMirror.setStyle(hoverStyle);
  this._hoverElements.push(elMirror);
  + }
  +
  + elMirror.setStyle(hoverStyle);
  },
  removeHover: function (el) {
  