### Question:
Cluster { public static Cluster bootstrap(List<InetSocketAddress> addresses) { List<Node> nodes = new ArrayList<>(); int nodeId = -1; for (InetSocketAddress address : addresses) nodes.add(new Node(nodeId--, address.getHostString(), address.getPort())); return new Cluster(null, true, nodes, new ArrayList<PartitionInfo>(0), Collections.<String>emptySet(), Collections.<String>emptySet(), null); } Cluster(String clusterId,
                   Collection<Node> nodes,
                   Collection<PartitionInfo> partitions,
                   Set<String> unauthorizedTopics,
                   Set<String> internalTopics);  Cluster(String clusterId,
                   Collection<Node> nodes,
                   Collection<PartitionInfo> partitions,
                   Set<String> unauthorizedTopics,
                   Set<String> internalTopics,
                   Node controller); private  Cluster(String clusterId,
                    boolean isBootstrapConfigured,
                    Collection<Node> nodes,
                    Collection<PartitionInfo> partitions,
                    Set<String> unauthorizedTopics,
                    Set<String> internalTopics,
                    Node controller); static Cluster empty(); static Cluster bootstrap(List<InetSocketAddress> addresses); Cluster withPartitions(Map<TopicPartition, PartitionInfo> partitions); List<Node> nodes(); Node nodeById(int id); Node leaderFor(TopicPartition topicPartition); PartitionInfo partition(TopicPartition topicPartition); List<PartitionInfo> partitionsForTopic(String topic); Integer partitionCountForTopic(String topic); List<PartitionInfo> availablePartitionsForTopic(String topic); List<PartitionInfo> partitionsForNode(int nodeId); Set<String> topics(); Set<String> unauthorizedTopics(); Set<String> internalTopics(); boolean isBootstrapConfigured(); ClusterResource clusterResource(); Node controller(); @Override String toString();  }### Answer:
@Test public void testBootstrap() { String ipAddress = "140.211.11.105"; String hostName = "www.example.com"; Cluster cluster = Cluster.bootstrap(Arrays.asList( new InetSocketAddress(ipAddress, 9002), new InetSocketAddress(hostName, 9002) )); Set<String> expectedHosts = Utils.mkSet(ipAddress, hostName); Set<String> actualHosts = new HashSet<>(); for (Node node : cluster.nodes()) actualHosts.add(node.host()); assertEquals(expectedHosts, actualHosts); }