def render_row(row_index, widths)
      @pad + @page_data.each_with_index.map do |column, index|
        column[row_index].to_s.ljust(widths[index])
      end.join(" ")
    end
def render_row(row_index, widths)
      @pad + @page_data.each_with_index.map do |column, index|
        column[row_index].to_s.ljust(widths[index])
      end.join(" ")
    end
Render a single row of data.
 Returns: A string.