public ApplicationReindexing withReady(String cluster, String documentType, Instant readyAt, double speed, String cause) {
        if (speed <= 0)
            throw new IllegalArgumentException("Initial reindexing speed must be in (0, 10], but was " + speed);

        Cluster current = clusters.getOrDefault(cluster, Cluster.empty());
        Cluster modified = new Cluster(current.pending,
                                       with(documentType, new Status(readyAt, speed, cause), current.ready));
        return new ApplicationReindexing(enabled, with(cluster, modified, clusters));
    }
Returns a copy of this with reindexing for the given document type in the given cluster ready at the given instant.
configserver/src/main/java/com/yahoo/vespa/config/server/application/ApplicationReindexing.java