A parsed-JSON payload (a PHP fragment's reply, a migrator step, a GC ledger, an updb beat). any values, not unknown: callers add fields after the fact and casts would not be safer.
any
unknown
A parsed-JSON payload (a PHP fragment's reply, a migrator step, a GC ledger, an updb beat).
anyvalues, notunknown: callers add fields after the fact and casts would not be safer.