async def fetch_open_orders(self, symbol=None, since=None, limit=None, params={}):
    if (symbol is None):
        raise ArgumentsRequired((self.id + ': fetchOpenOrders requires a `symbol` argument.'))
    (await self.load_markets())
    market = self.market(symbol)
    request = self.create_paginated_request(market, since, limit)
    response = (await self.privatePostOrderOpen(self.extend(request, params)))
    return self.parse_orders(response['orders'], market)
async def fetch_open_orders(self, symbol=None, since=None, limit=None, params={}):
    if (symbol is None):
        raise ArgumentsRequired((self.id + ': fetchOpenOrders requires a `symbol` argument.'))
    (await self.load_markets())
    market = self.market(symbol)
    request = self.create_paginated_request(market, since, limit)
    response = (await self.privatePostOrderOpen(self.extend(request, params)))
    return self.parse_orders(response['orders'], market)