async def fetch_order_book(self, symbol, limit=None, params={}):
    (await self.load_markets())
    market = self.market(symbol)
    request = {'id': market['id']}
    response = (await self.publicGetMarketIdOrderbook(self.extend(request, params)))
    timestamp = self.safe_integer(response, 'timestamp')
    if (timestamp is not None):
        timestamp *= 1000
    return self.parse_order_book(response, timestamp)
async def fetch_order_book(self, symbol, limit=None, params={}):
    (await self.load_markets())
    market = self.market(symbol)
    request = {'id': market['id']}
    response = (await self.publicGetMarketIdOrderbook(self.extend(request, params)))
    timestamp = self.safe_integer(response, 'timestamp')
    if (timestamp is not None):
        timestamp *= 1000
    return self.parse_order_book(response, timestamp)