[[!comment format=mdwn
 username="spwhitton"
 avatar="http://cdn.libravatar.org/avatar/9c3f08f80e67733fd506c353239569eb"
 subject="comment 1"
 date="2018-08-24T23:12:17Z"
 content="""
The existing properties cannot do what you want.  You are going to need to write a new one.  Simplest implementation would be something that calls `apt-get install foo=1.2.3`.
"""]]
