### Question:
ZergHosts { public ImmutableSet<CassandraInstance> toCassandraInstances() { return FluentIterable.from(hosts).transform(TO_CASSANDRA_INSTANCE).filter(VALID_INSTANCE).toSet(); } private  ZergHosts(ImmutableSet<ZergHost> hosts); static ZergHosts from(Collection<ZergHost> hosts); static @Nullable CassandraInstance toCassandraInstance(ZergHost host); ImmutableSet<String> rings(); ZergHosts filterRing(final String ring); ZergHosts filterRegion(final String region); ZergHosts filterScope(Map<String, String> ringScopes, String region, String ring); ImmutableSet<ZergHost> toSet(); ImmutableSet<CassandraInstance> toCassandraInstances();  }### Answer:
@Test public void toCassandraInstances() { assertEquals(INSTANCES, ZergHosts.from(HOSTS).toCassandraInstances()); }