code: public static <R> Publisher<R> parallelizePublisher(IntSet segments, Executor executor,
           IntFunction<Publisher<R>> publisherFunction) {
        return org.infinispan.persistence.internal.PersistenceUtil.parallelizePublisher(segments, Schedulers.from(executor),
              publisherFunction);
     }
docs: Will create a publisher that parallelizes each publisher returned from the <b>publisherFunction</b> by executing
  them on the executor as needed.
  <p>
  Note that returned publisher will be publishing entries from the invocation of the executor. Thus any subscription
  will not block the thread it was invoked on, unless explicitly configured to do so.
  @param segments segments to parallelize across
  @param executor the executor execute parallelized operations on
  @param publisherFunction function that creates a different publisher for each segment
  @param <R> the returned value
  @return a publisher that