def fetch_trading_fee(self, symbol, params={}):
    if (not self.has['fetchTradingFees']):
        self.raise_error(NotSupported, details='fetch_trading_fee() not supported yet')
    return self.fetch_trading_fees(params)
def fetch_trading_fee(self, symbol, params={}):
    if (not self.has['fetchTradingFees']):
        self.raise_error(NotSupported, details='fetch_trading_fee() not supported yet')
    return self.fetch_trading_fees(params)