def set_fan_mode(self, index, fan_mode, cool_temp, heat_temp, hold_type="nextTransition"):
        ''' Set fan mode. Values: auto, minontime, on '''
        body = {"selection": {
                    "selectionType": "thermostats",
                    "selectionMatch": self.thermostats[index]['identifier']},
                "functions": [{"type": "setHold", "params": {
                    "holdType": hold_type,
                    "coolHoldTemp": int(cool_temp * 10),
                    "heatHoldTemp": int(heat_temp * 10),
                    "fan": fan_mode
                }}]}
        log_msg_action = "set fan mode"
        return self.make_request(body, log_msg_action)
Set fan mode. Values: auto, minontime, on