### Question:
CentralizedManifest implements Manifest { public int size() { if (defaultRule != null) { return rules.size() + 1; } return rules.size(); } CentralizedManifest(); LinkedHashMap<String, CentralizedRule> getRules(); @Nullable CentralizedRule getDefaultRule(); boolean isExpired(Instant now); int size(); @Override // TODO(anuraaga): It seems like this should never return null, check where defaultRule is guaranteed to be present and remove @Nullable Rule match(SamplingRequest req, Instant now); void putRules(List<SamplingRule> inputs, Instant now); List<SamplingStatisticsDocument> snapshots(Instant now); void putTargets(List<SamplingTargetDocument> targets, Instant now);  }### Answer:
@Test void testEmptyManifestSize() { CentralizedManifest manifest = new CentralizedManifest(); Assertions.assertEquals(0, manifest.size()); }