Как можно стримить сразу несколько акций Tinkoff Api Invest

Нужно стримить сразу несколько акций через API Tinkoff Invest. Как можно это организовать, типа несколько итераторов?

import time

from tinkoff.invest import (
    Client,
    MarketDataRequest,
    OrderBookInstrument,
    SubscribeCandlesRequest,
    SubscribeOrderBookRequest,
    SubscriptionAction,
    SubscriptionInterval,
)

TOKEN = "**********************************"

t = True
def main():
    def request_iterator():
        yield MarketDataRequest(
            subscribe_order_book_request=SubscribeOrderBookRequest(
                subscription_action=SubscriptionAction.SUBSCRIPTION_ACTION_SUBSCRIBE,
                instruments=[
                    OrderBookInstrument(
                        figi="BBG00178PGX3",
                        depth = 1,
                        #interval=SubscriptionInterval.SUBSCRIPTION_INTERVAL_ONE_MINUTE,
                    )
                ],
            )
        )
        time.sleep(1)

    with Client(TOKEN) as client:
        while t == True:
            for marketdata in client.market_data_stream.market_data_stream(
                request_iterator()
            ):
                if (marketdata.orderbook == None):
                        continue
            #bids = marketdata.orderbook.bids
            #print(marketdata)
                price = marketdata.orderbook.bids.__getitem__(0).__getattribute__('price')
                lots = marketdata.orderbook.bids.__getitem__(0).__getattribute__('quantity')
                print(price.units + price.nano / 1e9, lots)
            #print(bids.__getitem__(0).__getattribute__('price')) 
#t = True

if __name__ == "__main__":
    main()