### Question:
TransactionHookManager { public static List<TransactionHook> getHooks() throws IllegalStateException { List<TransactionHook> hooks = LOCAL_HOOKS.get(); if (hooks == null || hooks.isEmpty()) { return Collections.emptyList(); } return Collections.unmodifiableList(hooks); } private  TransactionHookManager(); static List<TransactionHook> getHooks(); static void registerHook(TransactionHook transactionHook); static void clear();  }### Answer:
@Test public void testGetHooks() { assertThat(TransactionHookManager.getHooks()).isEmpty(); TransactionHookManager.registerHook(new TransactionHookAdapter()); assertThat(TransactionHookManager.getHooks()).isNotEmpty(); }