How to use the zoomus.util.date_to_str function in zoomus

def test_can_convert_date_to_str(self):
        d = datetime.date(year=2015, month=12, day=8)
        self.assertEqual(util.date_to_str(d), "2015-12-08T00:00:00Z")

def test_can_convert_datetime_to_str(self):
        d = datetime.datetime(year=2015, month=12, day=8, hour=23, minute=21, second=37)
        self.assertEqual(util.date_to_str(d), "2015-12-08T23:21:37Z")

def list(self, **kwargs):
        util.require_keys(kwargs, "host_id")
        if kwargs.get("start_time"):
            kwargs["start_time"] = util.date_to_str(kwargs["start_time"])
        return self.post_request("/webinar/list", params=kwargs)

def get_account_report(self, **kwargs):
        util.require_keys(kwargs, ["start_time", "end_time"])
        kwargs["from"] = util.date_to_str(kwargs["start_time"])
        del kwargs["start_time"]
        kwargs["to"] = util.date_to_str(kwargs["end_time"])
        del kwargs["end_time"]
        return self.get_request("/report/users", params=kwargs)

def list(self, **kwargs):
        util.require_keys(kwargs, "host_id")
        if kwargs.get("start_time"):
            kwargs["start_time"] = util.date_to_str(kwargs["start_time"])
        return self.post_request("/meeting/list", params=kwargs)

def list(self, **kwargs):
        util.require_keys(kwargs, "user_id")
        start = kwargs.pop("start", None)
        if start:
            kwargs["from"] = util.date_to_str(start)
        end = kwargs.pop("end", None)
        if end:
            kwargs["to"] = util.date_to_str(end)
        return self.get_request(
            "/users/{}/recordings".format(kwargs.get("user_id")), params=kwargs
        )

def update(self, **kwargs):
        util.require_keys(kwargs, ["id", "host_id"])
        if kwargs.get("start_time"):
            kwargs["start_time"] = util.date_to_str(kwargs["start_time"])
        return self.post_request("/webinar/update", params=kwargs)

def upcoming(self, **kwargs):
        util.require_keys(kwargs, "host_id")
        if kwargs.get("start_time"):
            kwargs["start_time"] = util.date_to_str(kwargs["start_time"])
        return self.post_request("/webinar/list/registration", params=kwargs)

def list(self, **kwargs):
        util.require_keys(kwargs, "host_id")
        start = kwargs.pop("start", None)
        if start:
            kwargs["from"] = util.date_to_str(start)
        end = kwargs.pop("end", None)
        if end:
            kwargs["to"] = util.date_to_str(end)
        return self.post_request("/recording/list", params=kwargs)