WholeFileCacheSystem.ls() does not allow **kwargs (like refresh)

[Danferno]

Is there a reason WholeFileCacheSystem.ls() does not allow **kwargs such as refresh, whereas SimpleCacheFileSystem does?

[martindurant]

Passing through kwargs sounds like the right thing to do. Simplecache gets far more use than WholeFile, most people don't end up needing the metadata tracking.