ReadonlyencodeOptional ReadonlyinitialWhat a checkpoint of an older released format restores when it does not carry the part: the state a process of the build that wrote it held, where the fact the part carries did not exist yet. It is the truth about that process, never a guess about a value the older build stored — a part whose absence the older data cannot explain leaves this out, and such a checkpoint is refused. A checkpoint of the current format always carries every part and never uses it.
ReadonlykeyThe key the part's value is stored under; unique among the layer's parts.
ReadonlyrestoreOptional ReadonlyrestoreWhat the part does instead of restore when the restore is the app
returning from the background (restoreAsAppReturningFromBackgroundOf):
the part knows what its state does when the app comes back after being
away (the Android routing-map refresh, overdue while the app was away,
is sent as APP_RESUME). A part without it restores the same way for
every kind of restore.
One piece of a platform's own process state that a checkpoint carries (the Android recovery tickets, the login home's issued state). The platform installs its parts in
ProcessCheckpointRegistries; the checkpoint stores each part's value under its key and a restore hands it back.encodemust produce JSON; a failure is a defect of the part.