### Question:
IOManager implements UncaughtExceptionHandler { public Channel.Enumerator createChannelEnumerator() { return new Channel.Enumerator(this.paths, this.random); } IOManager();  IOManager(String tempDir);  IOManager(String[] paths); synchronized final void shutdown(); final boolean isProperlyShutDown(); @Override void uncaughtException(Thread t, Throwable e); Channel.ID createChannel(); Channel.Enumerator createChannelEnumerator(); BlockChannelWriter createBlockChannelWriter(Channel.ID channelID,
								LinkedBlockingQueue<MemorySegment> returnQueue); BlockChannelWriter createBlockChannelWriter(Channel.ID channelID,
								LinkedBlockingQueue<MemorySegment> returnQueue, int numRequestsToCombine); BlockChannelWriter createBlockChannelWriter(Channel.ID channelID); BlockChannelWriter createBlockChannelWriter(Channel.ID channelID, int numRequestsToCombine); BlockChannelReader createBlockChannelReader(Channel.ID channelID,
										LinkedBlockingQueue<MemorySegment> returnQueue); BlockChannelReader createBlockChannelReader(Channel.ID channelID,
					LinkedBlockingQueue<MemorySegment> returnQueue, int numRequestsToCombine); BlockChannelReader createBlockChannelReader(Channel.ID channelID); BlockChannelReader createBlockChannelReader(Channel.ID channelID, int numRequestsToCombine); BulkBlockChannelReader createBulkBlockChannelReader(Channel.ID channelID,
			List<MemorySegment> targetSegments,	int numBlocks);  }### Answer:
@Test public void channelEnumerator() { File tempPath = new File(System.getProperty("java.io.tmpdir")); Channel.Enumerator enumerator = ioManager.createChannelEnumerator(); for (int i = 0; i < 10; i++) { Channel.ID id = enumerator.next(); File path = new File(id.getPath()); Assert.assertTrue("Channel IDs must name an absolute path.", path.isAbsolute()); Assert.assertFalse("Channel IDs must name a file, not a directory.", path.isDirectory()); Assert.assertTrue("Path is not in the temp directory.", tempPath.equals(path.getParentFile())); } }