code: def make_simple_multi_country_equity_info(countries_to_sids,
                                            countries_to_exchanges,
                                            start_date,
                                            end_date):
      
      sids = []
      symbols = []
      exchanges = []
  
      for country, country_sids in countries_to_sids.items():
          exchange = countries_to_exchanges[country]
          for i, sid in enumerate(country_sids):
              sids.append(sid)
              symbols.append('-'.join([country, str(i)]))
              exchanges.append(exchange)
  
      return pd.DataFrame(
          {
              'symbol': symbols,
              'start_date': start_date,
              'end_date': end_date,
              'asset_name': symbols,
              'exchange': exchanges,
          },
          index=sids,
          columns=(
              'start_date',
              'end_date',
              'symbol',
              'exchange',
              'asset_name',
          ),
      )
docs: Create a DataFrame representing assets that exist for the full duration
      between `start_date` and `end_date`, from multiple countries.