### Question:
ChannelBufferManager { public Set<String> getActiveChannelCodes() { try { Set<String> channelCodeSet = new HashSet<String>(); if (subscribedChannels.keySet() != null && !subscribedChannels.keySet().isEmpty()) { for (String s:subscribedChannels.keySet()) { channelCodeSet.add(s.substring(CHANNEL_PREFIX_STRING.length())); } } return channelCodeSet; } catch (Exception e) { logger.error("Unable to get active channel codes"); } return null; } ChannelBufferManager(); void initiateChannelBufferManager(final String channelRegEx); ExecutorService getExecutorServicePool(); void initiateChannelBufferManager(final int bufferSize, final String channelRegEx); void manageChannelBuffersWrapper(final String subscriptionPattern, final String channelName, 
			final String receivedMessage); void manageChannelBuffers(final String subscriptionPattern, final String channelName, 
			final String receivedMessage); void addMessageToChannelBuffer(final String channelName, final String msg); List<String> getLastMessages(String channelName, int msgCount); boolean isChannelPresent(String channelName); void createChannelQueue(final String channelName); void deleteChannelBuffer(final String channelName); void deleteAllChannelBuffers(); Set<String> getActiveChannelsList(); Set<String> getActiveChannelCodes(); @SuppressWarnings("unchecked") Boolean getChannelPublicStatus(String channelName); @SuppressWarnings("unchecked") Map<String, Boolean> getAllRunningCollections(); List<String> getLatestFromAllChannels(final int msgCount); String parseChannelName(String channelName); void close(); static final int NO_DATA_TIMEOUT; static final int CHECK_INTERVAL; static final int CHECK_CHANNEL_PUBLIC_INTERVAL; static String redisHost; static int redisPort; static JedisConnectionObject jedisConn; static Jedis subscriberJedis; static RedisSubscriber aidrSubscriber; static final String CHANNEL_PREFIX_STRING; static ConcurrentHashMap<String, ChannelBuffer> subscribedChannels; }### Answer:
@Test public void getActiveChannelCodesTest() { Set<String> set = channelBufferManager.getActiveChannelCodes(); assertNotNull(set); assertEquals("mock_collection", set.iterator().next()); }