code: def fetch(self):
          
          params = values.of({})
  
          payload = self._version.fetch(
              'GET',
              self._uri,
              params=params,
          )
  
          return BalanceInstance(self._version, payload, account_sid=self._solution['account_sid'], )
docs: Fetch a BalanceInstance
  
          :returns: Fetched BalanceInstance
          :rtype: twilio.rest.api.v2010.account.balance.BalanceInstance