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