def add_rows(array_or_num)
      if array_or_num.is_a?(Array)
        array_or_num.each do |row|
          add_row(row)
        end
      else
        array_or_num.times do
          add_row
        end
      end
    end
Adds multiple rows to the data_table. You can call this method with data to populate a set of new rows or create new empty rows.

Parameters:
* array_or_num    [Required] Either an array or a number.
- Array: An array of row objects used to populate a set of new rows. Each row is an object as described in add_row().
- Number: A number specifying the number of new empty rows to create.