Code review comment for lp:~jimbaker/pyjuju/new-hook-semantics-1-departed-hook

Looks good to me, +1

[1] There are some pep8/style formatting issues, i've got a diff to fix here
https://pastebin.canonical.com/45766/

[2] Regarding gustavo's 2. Any error in a hook should exit processing as soon as possible, any error in the hook should be handled and as early possible. The hook executor will raise an errback on the execution deferred, and the workflow will transition to an error state. a recovery transition, will have to deal with partial state recoveries, but i think that's regardless of mechanism (although possible w/ btrfs snapshots pre transition would make a reasonable mechanism of partial minimization coupled with a multi hook execution flush of the associated hook api context buffers.