ctor(manaCounts) {
    cc.Node.prototype.ctor.call(this);

    const horizontalLineNode = new cc.DrawNode();
    horizontalLineNode.setAnchorPoint(0, 0);
    horizontalLineNode.drawSegment(cc.p(0, 0), cc.p(270 + this.barWidth, 0), 1.0, new cc.Color(255, 255, 255, 100));
    this.addChild(horizontalLineNode);

    this._columnNodes = [];

    for (let i = 0; i < 10; i++) {
      const columnLabel = new cc.LabelTTF(i.toString(), RSX.font_light.name, 14, cc.size(this.barWidth, 30), cc.TEXT_ALIGNMENT_CENTER);

      columnLabel.setAnchorPoint(0, 1);
      columnLabel.setPosition(i * 30, -5);
      this.addChild(columnLabel);

      const columnBar = new cc.DrawNode();
      columnBar.setAnchorPoint(0, 0);
      columnBar.setPosition(i * 30, 5);
      columnBar.drawRect(cc.p(0, 0), cc.p(this.barWidth, this.barUnitHeight), cc.color(100, 200, 255), 0, cc.color(0, 0, 0, 0));
      columnBar.setScaleY(0);
      this.addChild(columnBar);

      this._columnNodes.push(columnBar);
    }
  }
*************************************************************************
DeckHistogramNode
shows histogram for an array of SDK cards
**************************************************************************