static Class<? extends StoreFileTracker> getSrcTrackerClass(Configuration conf) {
    return StoreFileTrackerFactory.getStoreFileTrackerClassForMigration(conf, SRC_IMPL);
  }
A store file tracker used for migrating between store file tracker implementations.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/storefiletracker/MigrationStoreFileTracker.java