code: def update_task(self, id, new_lease_time, client=None):
          
          client = self._require_client(client)
          task = Task(taskqueue=self, id=id)
          try:
              response = client.connection.api_request(method='POST', path=self.path + "/tasks/" + id,
                                                       query_params={"newLeaseSeconds": new_lease_time},
                                                       _target_object=task)
              task._set_properties(response)
              return task
          except NotFound:
              return None
docs: Updates the duration of a task lease
  
          If the task isn't found (backend 404), raises a
          :class:`gcloud.exceptions.NotFound`.
  
          :type id: string
          :param id: A task name to update
  
          :type new_lease_time: int
          :param new_lease_time: New lease time, in seconds.
  
          :type client: :class:`gcloud.taskqueue.client.Client` or ``NoneType``
          :param client: Optional. The client to use.  If not passed, falls back
                         to the ``client`` stored on the task's taskqueue.
  
          :rtype: :class:`_Task`.
          :returns: a task
          :raises: :class:`gcloud.exceptions.NotFound`