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