private void updateTaskContextInfoSupplier(final String extraText) {
        taskContext.info(() -> {
            final String extraTextArg = extraText != null
                    ? " - " + extraText
                    : "";
            final String stateArg = migrationState != null
                    ? LogUtil.message(" - Migrated {} of {} maps, total entries migrated: {}",
                    migrationState.mapsMigrated.get(),
                    migrationState.totalMaps,
                    migrationState.entriesMigrated.get())
                    : "";

            return LogUtil.message("Migrating legacy ref data for reference stream {} into store {}{}{}",
                    refStreamId,
                    destinationStore.getName(),
                    extraTextArg,
                    stateArg);
        });
    }
Migrate the data for refStreamId into destinationStore
stroom-pipeline/src/main/java/stroom/pipeline/refdata/store/offheapstore/StoreMigrator.java