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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def send_request(self, method, url, headers=None, json_data=None, retry=True):
 """Send requests to Skybell."""

        if not self.cache(CONST.ACCESS_TOKEN) and url != CONST.LOGIN_URL:
            self.login()

        if not headers:
            headers = {}

        if self.cache(CONST.ACCESS_TOKEN):
            headers['Authorization'] = 'Bearer ' + \
                self.cache(CONST.ACCESS_TOKEN)

        headers['user-agent'] = (
            'SkyBell/3.4.1 (iPhone9,2; iOS 11.0; loc=en_US; lang=en-US) '
            'com.skybell.doorbell/1')
        headers['content-type'] = 'application/json'
        headers['accepts'] = '*/*'
        headers['x-skybell-app-id'] = self.cache(CONST.APP_ID)
        headers['x-skybell-client-id'] = self.cache(CONST.CLIENT_ID)

        _LOGGER.debug("HTTP %s %s Request with headers: %s",
                      method, url, headers)

        try:
            response = getattr(self._session, method)(
                url, headers=headers, json=json_data)
            _LOGGER.debug("%s %s", response, response.text)

            if response and response.status_code < 400:
                return response
        except RequestException as exc:
            _LOGGER.warning("Skybell request exception: %s", exc)

        if retry:
            self.login()

            return self.send_request(method, url, headers, json_data, False)

        raise SkybellException(ERROR.REQUEST, "Retry failed")