class StringColumn extends AbstractStringColumn<StringColumn> {

  @Override
  public StringColumn lead(int n) {
    StringColumn column = lag(-n);
    column.setName(name() + " lead(" + n + ")");
    return column;
  }

  private  StringColumn(String name, Collection<String> strings);
  private  StringColumn(String name, DictionaryMap map);
  private  StringColumn(String name);
  private  StringColumn(String name, String[] strings);

}