code: def raw_exchange_rates
        table_rows = Oga.parse_html(response.body).css('.row.row-wrapper')
        # EGB porvide 17 currencies (and a header row)
        fail ResponseError, 'Unknown HTML' unless table_rows&.size == 18
        table_rows.lazy.drop(1).map(&:children).map do |cell|
          cell.map(&:text).map(&:strip)
        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
     [
       ["", "USD", "", "17.00", "", "17.75", ""],
       ["", "EUR", "", "17.9639", "", "18.8896", ""],
       ["", "GBP", "", "20.9049", "", "22.0739", ""],
       ...
     ]