what each view served from it keeps off the wire
Optionalfutureoverrides ProvisionPrior.futureViews
layout, template and asset are shared by many pages; route is a page the server calls hot; expansion is a page the user has not asked for yet
Optionalmaintainwhat keeping it current costs over its life; none when omitted
what fetching it costs, once
Optionalreuseoverrides ProvisionPrior.reuse
something the worker could fetch ahead of the visit that needs it