The resolved (stored) shape.
The accepted input shape, which need not be P widened - a type may accept
convenience keys that its shorthand folds onto canonical ones and that never appear in P
(see IStyledFont.Modifiers). Defaults to TypedObject.ResolvableProperties of P, and
is otherwise inferred from update; callers are expected to have already type-checked the
update against their own public modifier type.
OptionalupdateFrom: PIf true, an explicit null in the update is recorded in the result (a
'tombstone') instead of being dropped. Without this, 'explicitly cleared' and 'never mentioned'
are indistinguishable in the resolved object. Used when resolving an update against nothing to
build a reusable update template; the tombstones are honored (and dropped) by a later resolve
against a real updateFrom.
Merged updates into updatesFrom. It used the template for values and the typedObject for navigating.