public static void registerHook(TransactionHook transactionHook) {
        if (transactionHook == null) {
            throw new NullPointerException("transactionHook must not be null");
        }
        List<TransactionHook> transactionHooks = LOCAL_HOOKS.get();
        if (transactionHooks == null) {
            LOCAL_HOOKS.set(new ArrayList<>());
        }
        LOCAL_HOOKS.get().add(transactionHook);
    }
@Test
    public void testNPE() {
        Assertions.assertThrows(NullPointerException.class, () -> TransactionHookManager.registerHook(null));
    }