How to use the plugwise.Circle function in plugwise

def update(self):
        """Get the latest data from the plugwise circles."""
        import plugwise

        self.current_consumption = plugwise.Circle(self.mac, self.stick).get_power_usage()
        _LOGGER.debug("Current Consumption: %s", self.current_consumption)

        self.getinfo = plugwise.Circle(self.mac, self.stick).get_info()
        self.state = self.getinfo['relay_state']
        self.fwversion = self.getinfo['fw_ver']
        self.datetime = self.getinfo['datetime']
        _LOGGER.debug("Relay State: %s", self.state)
        return

def switch_off(self):
        """Turn the switch off."""
        import plugwise
        plugwise.Circle(self.mac, self.stick).switch_off()

def update(self):
        """Get the latest data from the plugwise circles."""
        import plugwise

        self.current_consumption = plugwise.Circle(self.mac, self.stick).get_power_usage()
        _LOGGER.debug("Current Consumption: %s", self.current_consumption)

        self.getinfo = plugwise.Circle(self.mac, self.stick).get_info()
        self.state = self.getinfo['relay_state']
        self.fwversion = self.getinfo['fw_ver']
        self.datetime = self.getinfo['datetime']
        _LOGGER.debug("Relay State: %s", self.state)
        return

def switch_on(self):
        """Turn the switch on."""
        import plugwise
        plugwise.Circle(self.mac, self.stick).switch_on()