### Question:
LocalKeyValueStoreService implements KeyValueStoreService<T> { @Override public void delete(final String key) { cache.remove(key); writeBehindWriter.delete(key); } LocalKeyValueStoreService(
            final Reactor reactor,
            final Timer timer,
            final FallbackReader<T> fallbackReader,
            final WriteBehindWriter<T> writeBehindWriter,
            final int cacheSize,
            final Duration flushEvery,
            final StatsCollector statsCollector,
            final String statKey,
            final Duration debugInterval,
            final boolean debug); @Override void put(final String key,
                    final T value); @Override void putWithConfirmation(final Callback<Boolean> confirmation,
                                    final String key,
                                    final T value); @Override void putWithConfirmationAndTimeout(final Callback<Boolean> confirmation,
                                              final String key,
                                              final T value,
                                              final Duration expiry); @Override void putWithTimeout(final String key,
                               final T value,
                               final Duration expiry); @Override void get(final Callback<Optional<T>> callback,
                    final String key); @Override void hasKey(final Callback<Boolean> hasKeyCallback, final String key); @Override void delete(final String key); @Override void deleteWithConfirmation(Callback<Boolean> confirmation, String key); @Override void wipeCache(); @QueueCallback({QueueCallbackType.EMPTY, QueueCallbackType.LIMIT, QueueCallbackType.IDLE}) void process();  }### Answer:
@Test public void testDelete() throws InterruptedException { kvStore.put("testKey3", new Todo("testValue3")); ServiceProxyUtils.flushServiceProxy(kvStore); Sys.sleep(100); final Optional<Todo> todoOptional = getTodoForKey("testKey3"); assertTrue(todoOptional.isPresent()); assertEquals("testValue3", todoOptional.get().name); final Optional<String> todoForKeyFromBacking = getTodoForKeyFromBacking("testKey3"); assertTrue(todoForKeyFromBacking.isPresent()); assertEquals("{\"name\":\"testValue3\"}", todoForKeyFromBacking.get()); kvStore.delete("testKey3"); ServiceProxyUtils.flushServiceProxy(kvStore); Sys.sleep(100); final Optional<Todo> todoOptional2 = getTodoForKey("testKey3"); assertFalse(todoOptional2.isPresent()); final Optional<String> todoForKeyFromBacking2 = getTodoForKeyFromBacking("testKey3"); assertFalse(todoForKeyFromBacking2.isPresent()); }