'Return all IDs of the orders in the orderbook, both asks and bids. The returned list is sorted.
:rtype: [OrderId]'

def get_order_ids(self):

    ids = []
    for (price_wallet_id, quantity_wallet_id) in self.asks.get_price_level_list_wallets():
        for (_, price_level) in self.asks.get_price_level_list(price_wallet_id, quantity_wallet_id).items():
            for ask in price_level:
                ids.append(ask.tick.order_id)
    for (price_wallet_id, quantity_wallet_id) in self.bids.get_price_level_list_wallets():
        for (_, price_level) in self.bids.get_price_level_list(price_wallet_id, quantity_wallet_id).items():
            for bid in price_level:
                ids.append(bid.tick.order_id)
    return sorted(ids)
