// Now user drills down on Publish Year/2010:
FacetSearchParams fsp = new FacetSearchParams(new CountFacetRequest(new CategoryPath("Author"), 10));
DrillDownQuery q = new DrillDownQuery(fsp.indexingParams, new MatchAllDocsQuery());
q.add(new CategoryPath("Publish Year/2010", '/'));
FacetsCollector fc = FacetsCollector.create(new SortedSetDocValuesAccumulator(state, fsp));
searcher.search(q, fc);
// Retrieve results
List<FacetResult> facetResults = fc.getFacetResults();
indexReader.close();
return facetResults;
}