Edit: Release 1.1.3.0 contains the fix for this issue.
There is currently a GitHub issue for this request:
Complete methods for object metadata
As of right now, the feature has been implemented in the Rackspace fork of the project, but has not yet been merged into the main project yet. I know the RackConnect team at Rackspace is working on getting a new release out within the next few days, so stay tuned!
Disclaimer: I work at Rackspace, though not on the RackConnect team.