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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 update_webhook(self, url, headers=None):
 """Register new webhook for incoming subscriptions. If a webhook is already set, this will do an overwrite. :param str url: the URL with listening webhook (Required) :param dict headers: K/V dict with additional headers to send with request :return: void """

        headers = headers or {}
        api = self._get_api(mds.NotificationsApi)

        # Delete notifications channel
        api.delete_long_poll_channel()

        # Send the request to register the webhook
        webhook_obj = WebhookData(url=url, headers=headers)
        api.register_webhook(webhook_obj)
        return