}

    @Test
    @DisplayName("Constructor should handle null tree handle")
    void testConstructor_NullTreeHandle_ThrowsNPE() throws Exception {
        // Given: Valid parent but null tree handle
        when(locator.getType()).thenReturn(SmbConstants.TYPE_WORKGROUP);
        when(locator.getURL()).thenReturn(createSmbURL("smb://"));

   *     for the keys
   */
  @CanIgnoreReturnValue
  public @Nullable V erase(@Nullable Object rowKey, @Nullable Object columnKey) {
    Integer rowIndex = rowKeyToIndex.get(rowKey);
    Integer columnIndex = columnKeyToIndex.get(columnKey);
    if (rowIndex == null || columnIndex == null) {
      return null;
    }

            long id = 0;
            String line = null;
            while ((line = reader.readLine()) != null) {
                // Remove comments
                final String replacedLine = line.replaceAll("#.*$", StringUtil.EMPTY).trim();

                // Skip empty lines or comment lines
                if (replacedLine.length() == 0) {
                    if (updater != null) {
                        updater.write(line);

```

### 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");

            if (responseData == null) {
                return null;
            }

            for (Rule rule : rules) {
                if (rule != null && rule.match(responseData)) {
                    return rule;
                }
            }
            return null;
        }

        @Override
        public void addRule(Rule rule) {
            if (rule != null) {
                rules.add(rule);

         * available. That API is accessed via reflection to make this independent
         * of the runtime JRE
         */
        if (EXT_GSS_CONTEXT_CLASS == null || INQUIRE_SEC_CONTEXT == null || INQUIRE_TYPE_SESSION_KEY == null) {
            throw new SmbException("ExtendedGSSContext support not available from JRE");
        }
        if (EXT_GSS_CONTEXT_CLASS.isAssignableFrom(this.gssContext.getClass())) {

      getMap().putIfAbsent(k0(), null);
    } catch (NullPointerException tolerated) {
    }
    expectUnchanged();
    expectNullValueMissingWhenNullValuesUnsupported(
        "Should not contain null after unsupported putIfAbsent(present, null)");
  }

  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_VALUES})
  public void testPut_nullValueSupported() {
    Entry<K, V> nullValueEntry = entry(k3(), null);
    assertNull(

    protected CrawlerClientFactory crawlerClientFactory = null;

    public WebConfig() {
        setBoost(1.0f);
    }

    @Override
    public String getDocumentBoost() {
        return getBoost().toString();
    }

    @Override
    public String getIndexingTarget(final String input) {
        if (includedDocUrlPatterns == null || excludedDocUrlPatterns == null) {
            initDocUrlPattern();
        }

        }

        @Test
        @DisplayName("Null parent with non-empty iterator causes NullPointerException during adapt")
        void nullParent_throwsNPE() {
            List<FileEntry> entries = Collections.singletonList(entry("x", SmbConstants.TYPE_SHARE));
            assertThrows(NullPointerException.class, () -> new ShareEnumIterator(null, entries.iterator(), null));
        }

     */
    if (result == null) {
      return null;
    } else {
      return (V) result;
    }
  }

  static @Nullable Object get(
      @Nullable Object hashTableObject,
      @Nullable Object[] alternatingKeysAndValues,
      int size,
      int keyOffset,
      @Nullable Object key) {
    if (key == null) {
      return null;
    } else if (size == 1) {