public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof XYBubbleRenderer)) {
            return false;
        }
        XYBubbleRenderer that = (XYBubbleRenderer) obj;
        if (this.scaleType != that.scaleType) {
            return false;
        }
        return super.equals(obj);