code: def update_activity(self, activity_id, activity_name=None, desc=None,
                          started_on=None, ended_on=None):
          
          put_data = {
              "name": activity_name,
              "description": desc,
              "started_on": started_on,
              "ended_on": ended_on
          }
          return self._put("/activities/" + activity_id, put_data)
docs: Send PUT request to /activities/{activity_id} to update the activity metadata.
          Raises ValueError if at least one field is not updated.
          :param activity_id: str uuid of activity
          :param activity_name: str new name of the activity (optional)
          :param desc: str description of the activity (optional)
          :param started_on: str date the updated activity began on (optional)
          :param ended_on: str date the updated activity ended on (optional)
          :return: requests.Response containing the successful result