[[!comment format=mdwn
 username="joey"
 subject="""comment 4"""
 date="2015-05-01T19:38:36Z"
 content="""
@madduck, you could file a todo if you want about that.

However, I have my doubts; if the json supposed to include the full set of
metadata for the file? If so, that seems a potentially expensive interface.
If not, it would be hard to tell when metadata should be deleted, or when
multiple values are being set, vs a value being changed. 

The current interface to set metadata deals with these possibilities in a
compact and sensible way.
"""]]