} else if (previousValue instanceof PredAndSucc) {
      adjacentNodeValues.put((N) node, PRED);
      removedValue = ((PredAndSucc) previousValue).successorValue;
    } else { // successor
      adjacentNodeValues.remove(node);
      removedValue = previousValue;
    }

    if (removedValue != null) {
      checkNonNegative(--successorCount);

      if (orderedNodeConnections != null) {

                    .thenReturn(null);

            // Perform the renewal
            boolean renewed = wrapper.renewCredentials("locationHint", null);

            // Verify that NtlmAuthenticator was used but credentials were not updated
            assertFalse(renewed, "renewCredentials should return false when NtlmAuthenticator returns null");

    TestCallable secondCallable = new TestCallable(Futures.<Void>immediateFuture(null));
    @SuppressWarnings({"unused", "nullness"})
    Future<?> possiblyIgnoredError1 = serializer.submitAsync(secondCallable, directExecutor());
    assertThat(firstCallable.called).isTrue();
    assertThat(secondCallable.called).isFalse();
    firstFuture.set(null);
    assertThat(secondCallable.called).isTrue();
  }

        factoryField.setAccessible(true);
        factoryField.set(null, null);

        // Clear the protocol handlers cache
        Field handlersField = Handler.class.getDeclaredField("PROTOCOL_HANDLERS");
        handlersField.setAccessible(true);
        @SuppressWarnings("unchecked")
        Map<String, URLStreamHandler> handlers = (Map<String, URLStreamHandler>) handlersField.get(null);
        handlers.clear();
    }

    /**

        // Test constructor with null message
        FessSystemException exception = new FessSystemException((String) null);

        assertNull(exception.getMessage());
        assertNull(exception.getCause());
    }

    public void test_constructor_withNullCause() {
        // Test constructor with null cause
        String message = "Test with null cause";

        return toFloat(o, null);
    }

    /**
     * Converts to {@link Float}.
     *
     * @param o
     *            The object to convert
     * @param pattern
     *            The pattern string
     * @return The converted {@link Float}
     */
    public static Float toFloat(final Object o, final String pattern) {
        if (o == null) {
            return null;

        this.sessionKey = sessionKey != null ? sessionKey.clone() : null;
        this.preauthIntegrityHash = preauthHash != null ? preauthHash.clone() : null;

        // Generate unique session ID for key management
        this.sessionId = String.format("smb-enc-%d-%d", System.currentTimeMillis(), secureRandom.nextLong());

        if (keyManager != null) {
            // Store keys securely

    assertNull("get(notPresent) should return null", get(k3()));
  }

  @MapFeature.Require(ALLOWS_NULL_KEY_QUERIES)
  public void testGet_nullNotContainedButAllowed() {
    assertNull("get(null) should return null", get(null));
  }

  @MapFeature.Require(absent = ALLOWS_NULL_KEY_QUERIES)
  public void testGet_nullNotContainedAndUnsupported() {
    try {
      assertNull("get(null) should return null or throw", get(null));

        // Create item and then set inputs to null via reflection or subclass
        CharMappingItem item = new CharMappingItem(1L, new String[] { "temp" }, "output") {
            @Override
            public String getInputsValue() {
                // Simulate null inputs scenario
                if (getInputs() == null) {
                    return super.getInputsValue();
                }

    assertNull("getOrDefault(absent, null) should return null", getMap().getOrDefault(k3(), null));
  }

  @MapFeature.Require(ALLOWS_NULL_KEY_QUERIES)
  public void testGetOrDefault_absentNull() {
    assertEquals(
        "getOrDefault(null, def) should return the default value",
        v3(),
        getMap().getOrDefault(null, v3()));
  }

  @MapFeature.Require(absent = ALLOWS_NULL_KEY_QUERIES)