public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof BubbleXYItemLabelGenerator)) {
            return false;
        }
        if (!super.equals(obj)) {
            return false;
        }
        BubbleXYItemLabelGenerator that = (BubbleXYItemLabelGenerator) obj;
        if (!ObjectUtilities.equal(this.zFormat, that.zFormat)) {
            return false;
        }
        if (!ObjectUtilities.equal(this.zDateFormat, that.zDateFormat)) {
            return false;
        }
        return true;