FutureDigest fget = peers[rnd.nextInt(100)].digest(lKey)
.from(new Number640(lKey, dKey, ckey, Number160.ZERO))
.to(new Number640(lKey, dKey, ckey, Number160.MAX_VALUE)).start();
fget.awaitUninterruptibly();
DigestResult dr = fget.digest();
NavigableMap<Number640, Collection<Number160>> fetchedDataMap = dr.keyDigest();
// verify fetched digest
Assert.assertEquals(dataMap.size(), fetchedDataMap.size());
for (Number640 key : dataMap.keySet()) {
Assert.assertTrue(fetchedDataMap.containsKey(key));