code: def set_heat_pump_mode(self, device_label, mode):
          
          response = None
          try:
              response = requests.put(
                  urls.set_heatpump_state(self._giid, device_label),
                  headers={
                      'Accept': 'application/json',
                      'Content-Type': 'application/json',
                      'Cookie': 'vid={}'.format(self._vid)},
                  data=json.dumps({'mode': mode}))
          except requests.exceptions.RequestException as ex:
              raise RequestError(ex)
          _validate_response(response)
          return json.loads(response.text)
docs: Set heatpump mode
          Args:
              mode (str): 'HEAT', 'COOL', 'FAN' or 'AUTO'