class TextColumn extends AbstractStringColumn<TextColumn> {

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

  private  TextColumn(String name, Collection<String> strings);
  private  TextColumn(String name);
  private  TextColumn(String name, String[] strings);

}