stateReaders

The state consumers among the subscriptions of context, by the reader name each reads the shared states with (ContextNode.stateReader), with the aggregate types it reads: a view is evicted once every reader of its type passed it, or it ages out. By default one reader named after this factory's class, of the types viewTypes names: it passes nothing unless its subscriptions read under that name, so their views only age out. A factory that overrides it also overrides viewTypes with the types it names.