SearchFilter search = new SearchEqualEnvelopes(index.getEnvelopeDecoder(), new Envelope(0, 2, 0, 3));
SearchResults results = index.searchIndex(search);
assertEquals(1, results.count());
search = new SearchCoveredByEnvelope(index.getEnvelopeDecoder(), new Envelope(9, 15, -1, 3));
results = index.searchIndex(search);
assertEquals(3, results.count());
index.clear(new NullListener());
assertEquals(0, index.count());