public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof AbstractPieItemLabelGenerator)) {
            return false;
        }

        AbstractPieItemLabelGenerator that
                = (AbstractPieItemLabelGenerator) obj;
        if (!this.labelFormat.equals(that.labelFormat)) {
            return false;
        }
        if (!this.numberFormat.equals(that.numberFormat)) {
            return false;
        }
        if (!this.percentFormat.equals(that.percentFormat)) {
            return false;
        }
        return true;