private void prvt_add(FacetIndexingParams iParams, RandomIndexWriter iw,
TaxonomyWriter tw, String... strings) throws IOException {
Document d = new Document();
FacetFields facetFields = new FacetFields(tw, iParams);
facetFields.addFields(d, Collections.singletonList(new CategoryPath(strings)));
d.add(new TextField("content", "alpha", Field.Store.YES));
iw.addDocument(d);
}
}