Number640 key = new Number640(key480, vKey);
Assert.assertTrue(dataMap.containsKey(key));
Assert.assertEquals(data.object(), dataMap.get(key).object());
// check digest result
DigestResult digestResult = fget.digest();
Assert.assertEquals(sortedMap.size(), digestResult.keyDigest().size());
for (Number160 versionKey : sortedMap.keySet()) {
Number640 digestKey = new Number640(locationKey, domainKey, contentKey, versionKey);
Assert.assertTrue(digestResult.keyDigest().containsKey(digestKey));
Assert.assertEquals(sortedMap.get(versionKey).basedOnSet().size(), digestResult