AWS S3 listKeys not standard?

[ecokisoli]

Hi. I've noticed that method listKeys does not return the same array structure between different adapters (Local and S3). Standard seems to be ['dirs' => [ ], 'keys' => [ ] ] whereas the AWS S3 adapter returns an array of the keys. As a result my code is not compatible when I switch from one adapter to the other.
Any thoughts about it?
My context is a Symfony project, with the following bundles:

• "knplabs/knp-gaufrette-bundle": "~0.5",
• "gaufrette/aws-s3-adapter": "~0.4"
  Thanks.