ctor(entityNode) {
    this._super(entityNode);

    // container nodes
    this._atkNode = new cc.Node();
    this._atkNode.setVisible(false);
    this.addChild(this._atkNode);

    this._hpNode = new cc.Node();
    this._hpNode.setVisible(false);
    this.addChild(this._hpNode);

    this._updateLayout();

    return true;
  }
*************************************************************************
StatsChangeNode
 - node used to show stat changes for an entity node
**************************************************************************