def add_a_row
      new_rows = rows + 1
      pool, @page_data = @page_data.flatten, []

      until pool.empty?
        @page_data << pool.shift(new_rows)
      end
    end
def add_a_row
      new_rows = rows + 1
      pool, @page_data = @page_data.flatten, []

      until pool.empty?
        @page_data << pool.shift(new_rows)
      end
    end
Add a row to the page, moving items as needed.