* {@link #rightValue} are not equal, and one but not both of them may be null.
   *
   * @since 2.0
   */
  @DoNotMock("Use Maps.difference")
  interface ValueDifference<V extends @Nullable Object> {
    /** Returns the value from the left map (possibly null). */
    @ParametricNullness
    V leftValue();

    /** Returns the value from the right map (possibly null). */
    @ParametricNullness
    V rightValue();

    /**

    }

    {
      ImmutableSet.Builder<String> builder = this.<String>builder();
      assertThrows(NullPointerException.class, () -> builder.add((String[]) null));
    }

    {
      ImmutableSet.Builder<String> builder = this.<String>builder();
      assertThrows(NullPointerException.class, () -> builder.add("a", (String) null));
    }

    {

          responseQueue.put(new Response(request.methodName, null, exception.getTargetException()));
          continue;
        } catch (Throwable throwable) {
          responseQueue.put(new Response(request.methodName, null, throwable));
          continue;
        }
        responseQueue.put(new Response(request.methodName, result, null));
      }
    } catch (ThreadDeath death) {
      return;

    super.setUp();
    this.equivalenceMock = new MockEquivalence();
    this.tester = EquivalenceTester.of(equivalenceMock);
  }

  /** Test null reference yields error */
  public void testOf_nullPointerException() {
    assertThrows(NullPointerException.class, () -> EquivalenceTester.of(null));
  }

  public void testTest_noData() {
    tester.test();
  }

  public void testTest() {

    super.setUp();
    this.equivalenceMock = new MockEquivalence();
    this.tester = EquivalenceTester.of(equivalenceMock);
  }

  /** Test null reference yields error */
  public void testOf_nullPointerException() {
    assertThrows(NullPointerException.class, () -> EquivalenceTester.of(null));
  }

  public void testTest_noData() {
    tester.test();
  }

  public void testTest() {

        final String msg = request.getHeader("Authorization");
        if (msg != null && (msg.startsWith("NTLM ") || offerBasic && msg.startsWith("Basic "))) {
            if (this.loadBalance) {
                dc = new UniAddress(getTransportContext().getNameServiceClient().getNbtByName(this.domainController, 0x1C, null));
            } else {

        Map<String, List<String>> headers = new HashMap<>();
        headers.put(null, Arrays.asList("value"));
        headers.put("Content-Type", Arrays.asList("application/json"));

        response.setHeaders(headers);

        Map<String, List<String>> result = response.getHeaders();
        assertNotNull(result);
        assertEquals(1, result.size()); // null key should be filtered out
        assertTrue(result.containsKey("content-type"));

                return Optional.empty();
            }

            @Override
            public Model parse(Source source, Map<String, ?> options) throws ModelParserException {
                return null;
            }
        }
    }

    @Nested
    class DiTest2 {

        PlexusContainer container;

        @BeforeEach
        void setup() throws Exception {

        while (!queue.isEmpty()) {
            final SearchLog searchLog = queue.poll();
            if (searchLog != null) {
                final String userAgent = searchLog.getUserAgent();
                final boolean isBot =
                        userAgent != null && stream(botNames).get(stream -> stream.anyMatch(botName -> userAgent.indexOf(botName) >= 0));
                if (!isBot) {

```

### Type Conversion
```java
import org.codelibs.core.convert.*;

// Safe type conversions with null handling
Integer value = IntegerConversionUtil.toInteger("123");        // Returns 123
Integer nullValue = IntegerConversionUtil.toInteger(null);     // Returns null
Boolean flag = BooleanConversionUtil.toBoolean("true");        // Returns true
Date date = DateConversionUtil.toDate("2023-12-25", "yyyy-MM-dd");