code: def create_subscription(self, client_id, client_secret, callback_url,
                              object_type=model.Subscription.OBJECT_TYPE_ACTIVITY,
                              aspect_type=model.Subscription.ASPECT_TYPE_CREATE,
                              verify_token=model.Subscription.VERIFY_TOKEN_DEFAULT):
          
          params = dict(client_id=client_id, client_secret=client_secret,
                        object_type=object_type, aspect_type=aspect_type,
                        callback_url=callback_url, verify_token=verify_token)
          raw = self.protocol.post('/push_subscriptions', use_webhook_server=True,
                                   **params)
          return model.Subscription.deserialize(raw, bind_client=self)
docs: Creates a webhook event subscription.
  
          http://strava.github.io/api/partner/v3/events/#create-a-subscription
  
          :param client_id: application's ID, obtained during registration
          :type client_id: int
  
          :param client_secret: application's secret, obtained during registration
          :type client_secret: str
  
          :param callback_url: callback URL where Strava will first send a GET request to validate, then subsequently send POST requests with updates
          :type callback_url: str
  
          :param object_type: object_type (currently only `activity` is supported)
          :type object_type: str
  
          :param aspect_type: object_type (currently only `create` is supported)
          :type aspect_type: str
  
          :param verify_token: a token you can use to verify Strava's GET callback request
          :type verify_token: str
  
          :return: An instance of :class:`stravalib.model.Subscription`.
          :rtype: :class:`stravalib.model.Subscription`
  
          Notes:
  
          `object_type` and `aspect_type` are given defaults because there is currently only one valid value for each.
  
          `verify_token` is set to a default in the event that the author doesn't want to specify one.
  
          The appliction must have permission to make use of the webhook API. Access can be requested by contacting developers -at- strava.com.