User user = createTestUser("testuser");
        try {
            authenticationManager.insert(user);
            fail("Should throw NullPointerException when processing null chain");
        } catch (NullPointerException e) {
            // Expected behavior when null chain is processed
            assertTrue(true);
        }
    }

    // Test chains order preservation

            // Then
            assertNotNull(cancel);
            assertEquals(mid, cancel.getMid());
        }

        @Test
        @DisplayName("Should throw NullPointerException when config is null")
        void testNullConfigurationThrowsException() throws Exception {
            // Given

    }

    public void test_execute_withNullPointerException() {
        // Setup mock SearchLogHelper that throws NullPointerException
        SearchLogHelper mockSearchLogHelper = new SearchLogHelper() {
            @Override
            public void storeSearchLog() {
                throw new NullPointerException("Null value encountered");
            }
        };
        ComponentUtil.register(mockSearchLogHelper, "searchLogHelper");

     * Returns the value of a specific attribute.
     *
     * @param name the name of the attribute to retrieve
     * @return the attribute value, or {@code null} if the attribute doesn't exist
     * @throws NullPointerException if name is null
     */
    @Nullable
    String attribute(@Nonnull String name);

    /**
     * Returns an immutable list of all child nodes.
     *

    }

    @Test
    @DisplayName("accept: rejects null input with meaningful NullPointerException")
    void accept_rejectsNullInput() {
        // Arrange: defensive filter that validates input
        SmbFileFilter filter = f -> {
            if (f == null) {
                throw new NullPointerException("file must not be null");
            }
            return true; // not reached in this test
        };

    }

    @Test
    @DisplayName("openConnection with null URL throws NullPointerException")
    void testOpenConnection_NullInput() {
        // Arrange
        Handler handler = newHandlerWith(mockCtx);

        // Act & Assert
        assertThrows(NullPointerException.class, () -> handler.openConnection(null), "Null URL should throw NPE");

  public void testCheckNotNull_simple_failure() {
    assertThrows(NullPointerException.class, () -> checkNotNull(null));
  }

  public void testCheckNotNull_simpleMessage_success() {
    String result = checkNotNull(NON_NULL_STRING, IGNORE_ME);
    assertSame(NON_NULL_STRING, result);
  }

  public void testCheckNotNull_simpleMessage_failure() {
    NullPointerException expected =

  public void testCheckNotNull_simple_failure() {
    assertThrows(NullPointerException.class, () -> checkNotNull(null));
  }

  public void testCheckNotNull_simpleMessage_success() {
    String result = checkNotNull(NON_NULL_STRING, IGNORE_ME);
    assertSame(NON_NULL_STRING, result);
  }

  public void testCheckNotNull_simpleMessage_failure() {
    NullPointerException expected =

    assertThrows(NullPointerException.class, () -> builder.put(null, 1));
    assertThrows(NullPointerException.class, () -> builder.putAll(null, Arrays.asList(1, 2, 3)));
    assertThrows(NullPointerException.class, () -> builder.putAll(null, 1, 2, 3));
    assertThrows(
        NullPointerException.class, () -> builder.putAll((Multimap<String, Integer>) toPut));
  }

    super.setUp();

    empty = new Target(emptyCollection(), "empty");
    /*
     * We test that nullSingleton.retainAll(disjointList) does NOT throw a
     * NullPointerException when disjointList does not, so we can't use
     * MinimalCollection, which throws NullPointerException on calls to
     * contains(null).
     */
    List<E> disjointList = asList(e3(), e4());
    disjoint = new Target(disjointList, "disjoint");