code: public static String getReferenceSetId(String readGroupSetId, OfflineAuth auth)
        throws IOException {
      Genomics genomics = GenomicsFactory.builder().build().fromOfflineAuth(auth);
      ReadGroupSet readGroupSet = genomics.readgroupsets().get(readGroupSetId)
          .setFields("referenceSetId").execute();
      return readGroupSet.getReferenceSetId();
    }
docs: Gets the ReferenceSetId for a given readGroupSetId using the Genomics API.
  
  @param readGroupSetId The id of the readGroupSet to query.
  @param auth The OfflineAuth for the API request.
  @return The referenceSetId for the redGroupSet (which may be null).
  @throws IOException