### Question:
InMemClusterMetadataStore implements ClusterMetadataStore { @Override public synchronized void updateClusterMetadata(ClusterMetadata clusterMetadata) { this.metadata = clusterMetadata; } InMemClusterMetadataStore(int numStorageContainers); @Override synchronized boolean initializeCluster(int numStorageContainers,
                                               Optional<String> segmentStorePath); @Override synchronized ClusterAssignmentData getClusterAssignmentData(); @Override synchronized void updateClusterAssignmentData(ClusterAssignmentData assignmentData); @Override synchronized void watchClusterAssignmentData(Consumer<Void> watcher, Executor executor); @Override synchronized void unwatchClusterAssignmentData(Consumer<Void> watcher); @Override synchronized ClusterMetadata getClusterMetadata(); @Override synchronized void updateClusterMetadata(ClusterMetadata clusterMetadata); @Override void close();  }### Answer:
@Test public void testUpdateClusterMetadata() { int numStorageContainers = 4096; ClusterMetadata metadata = ClusterMetadata.newBuilder() .setNumStorageContainers(numStorageContainers) .build(); store.updateClusterMetadata(metadata); assertEquals(metadata, store.getClusterMetadata()); }