code: public static List<CoverageBucket> getCoverageBuckets(String readGroupSetId, OfflineAuth auth)
        throws IOException {
      Genomics genomics = GenomicsFactory.builder().build().fromOfflineAuth(auth);
      ListCoverageBucketsResponse response =
          genomics.readgroupsets().coveragebuckets().list(readGroupSetId).execute();
      // Requests of this form return one result per reference name, so therefore many fewer than
      // the default page size, but verify that the assumption holds true.
      if (!Strings.isNullOrEmpty(response.getNextPageToken())) {
        throw new IllegalArgumentException("Read group set " + readGroupSetId
            + " has more Coverage Buckets than the default page size for the CoverageBuckets list operation.");
      }
      return response.getCoverageBuckets();
    }
docs: Gets the CoverageBuckets 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 list of reference bounds in the variantSet.
  @throws IOException