// create the index
IndexWriter indexWriter = new IndexWriter(indexDir, newIndexWriterConfig(TEST_VERSION_CURRENT, new MockAnalyzer(random())));
DirectoryTaxonomyWriter taxoWriter = new DirectoryTaxonomyWriter(taxoDir);
FacetFields facetFields = new FacetFields(taxoWriter);
Document doc = new Document();
facetFields.addFields(doc, Arrays.asList(new CategoryPath("A/1", '/')));
indexWriter.addDocument(doc);
IOUtils.close(indexWriter, taxoWriter);
DirectoryReader indexReader = DirectoryReader.open(indexDir);
TaxonomyReader taxoReader = new DirectoryTaxonomyReader(taxoDir);