public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof HistogramDataset)) {
            return false;
        }
        HistogramDataset that = (HistogramDataset) obj;
        if (!ObjectUtilities.equal(this.type, that.type)) {
            return false;
        }
        if (!ObjectUtilities.equal(this.list, that.list)) {
            return false;
        }
        return true;