I often like to add random blocks and stuff to villager trades but it's no good to roll for that on every plugin (Thus overshadowing normal villager trades). This allows to roll once for villager trades and then roll individually only if this master roll succeeds.
Normally I would fill out a lot of into here but this is an internal plugin so maybe later.
License: Do whatever you want as long as you credit me back (Apache 2)
Contributions always welcome, fork and send pull request.
More plugins to come.