Do I need `pull` settings when using plugins/s3-cache?

Documentation
1

I have a question about plugins/s3-cache.

There is pull: true config under the settings key.
http://plugins.drone.io/drone-plugins/drone-s3-cache/

But I found no document about this pull parameter.
Besides, it seems the key is not referred in the source code.

It would be good to remove the parameter from the document, if the parameter is not required.

Thanks.