class Table extends Relation implements Iterable<Row> {

  public Summarizer summarize(String columName, AggregateFunction<?, ?>... functions) {
    return summarize(column(columName), functions);
  }

  private  Table();
  private  Table(String name);
  protected  Table(String name, Column<?>... columns);
  protected  Table(String name, Collection<Column<?>> columns);

}