Contents:
A system for two phase updates: Update, and Commit.
ppb.features.twophase.
Commit
Fired after Update.
TwoPhaseMixin
Mixin to apply to objects to handle two phase updates.
on_commit
Commit changes previously staged.
stage_changes
Stage changes for the next commit.
These are just properties on the current object to update.
TwoPhaseSystem
Produces the Commit event.