Unfortunately, this wasn't a great name. The old one stunk, but the
new one was misleading at best. The thing is, this isn't about performing
an update -- it's about NOT doing an update, depending on its return value.
Further, it's not just previewing the changes, it is actively making a
decision on what to do in response to them. InspectUpdate seems to convey
this and I've unified the InspectUpdate and Update routines to take a
ChangeRequest, instead of UpdateRequest, to help imply the desired behavior.