static <T> SyncFetcherDelegate<T> fromReactive(ReactiveFetcher<T> fetcher) {
    return new SyncFetcherDelegate<T>(fetcher);
  }
Implementation of {@link SyncFetcher}. Also has some package-private methods
to allow delegation.
criteria/common/src/org/immutables/criteria/repository/sync/SyncFetcherDelegate.java