// Reused across documents, to add the necessary facet
// fields:
Document doc = new Document();
doc.add(new IntField("num", 10, Field.Store.NO));
doc.add(new FacetField("Author", "Bob"));
writer.addDocument(config.build(taxoWriter, doc));
doc = new Document();
doc.add(new IntField("num", 20, Field.Store.NO));
doc.add(new FacetField("Author", "Lisa"));
writer.addDocument(config.build(taxoWriter, doc));