code: def raw_exchange_rates
        table_rows = Oga.parse_html(response.body).css('#f_box option')
        # CAE porvide 17 currencies on the home page but with header
        # and an empty row in the end
        fail ResponseError, 'Unknown HTML' unless table_rows&.size == 17
        table_rows.lazy.map do |row|
          [
            row.text,
            row.attribute('data-buy').value,
            row.attribute('data-sell').value
          ]
        end
      end
docs: Send the request to the URL and retrun raw data of the response
   @return [Enumerator::Lazy] with the table row in HTML that evaluates to
     [
       ["QAR", "4.7367", "4.9294"],
       ["USD", "17.25", "17.95"]
       ...
     ]