class DoubleColumn extends NumberColumn<DoubleColumn, Double> implements NumberFillers<DoubleColumn> {

  @Override
  public DoubleColumn unique() {
    final DoubleSet doubles = new DoubleOpenHashSet();
    for (int i = 0; i < size(); i++) {
      doubles.add(getDouble(i));
    }
    final DoubleColumn column = DoubleColumn.create(name() + " Unique values");
    doubles.forEach((DoubleConsumer) column::append);
    return column;
  }

  protected  DoubleColumn(String name, DoubleArrayList data);
  protected  DoubleColumn(String name);

}