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

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

    @Test
    public void test_constructorWithNullMessageAndCause() {
        // Test constructor with null message and cause

    multimap().put(k3(), null);

    assertGet(k3(), Lists.newArrayList((V) null)); // ImmutableList.of can't take null.
    assertEquals(size + 1, multimap().size());
  }

  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_VALUES)
  public void testPutNullValue_unsupported() {
    assertThrows(NullPointerException.class, () -> multimap().put(k1(), null));

    expectUnchanged();
  }

    multimap().put(k3(), null);

    assertGet(k3(), Lists.newArrayList((V) null)); // ImmutableList.of can't take null.
    assertEquals(size + 1, multimap().size());
  }

  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_VALUES)
  public void testPutNullValue_unsupported() {
    assertThrows(NullPointerException.class, () -> multimap().put(k1(), null));

    expectUnchanged();
  }

    protected void assertObjectNotNull(String variableName, Object value) {
        if (variableName == null) {
            String msg = "The value should not be null: variableName=null value=" + value;
            throw new IllegalArgumentException(msg);
        }
        if (value == null) {
            String msg = "The value should not be null: variableName=" + variableName;
            throw new IllegalArgumentException(msg);
        }

     *
     * @param in the input file (must not be {@literal null})
     * @param inputEncoding the input file encoding (must not be {@literal null} or empty)
     * @param out the output file (must not be {@literal null})
     * @param outputEncoding the output file encoding (must not be {@literal null} or empty)
     * @return the number of characters copied
     */

   *
   * @param element the element to add one occurrence of; may be null only if explicitly allowed by
   *     the implementation
   * @return {@code true} always, since this call is required to modify the multiset, unlike other
   *     {@link Collection} types
   * @throws NullPointerException if {@code element} is null and this implementation does not permit
   *     null elements

        paramMap.put("url_exclude_pattern", ".*");

        try {
            indexUpdateCallback.isUrlCrawlable(paramMap, null);
            fail("Expected NullPointerException for null URL");
        } catch (NullPointerException e) {
            // Expected behavior - the method doesn't handle null URLs
        }
    }

    @Test
    public void test_isUrlCrawlable_nullUrlWithoutPattern() {

        if (path == null || loader == null) {
            return null;
        }
        final String p = getResourcePath(path, extension);
        return loader.getResource(p);
    }

    /**
     * Returns the resource as a stream from the context class loader.
     *
     * @param path
     *            The resource path. Must not be {@literal null} or empty string.
     * @return The input stream

     * @param dest The destination Bean. Must not be {@literal null}.
     */
    public static void copyBeanToBean(final Object src, final Object dest) {
        copyBeanToBean(src, dest, DEFAULT_OPTIONS);
    }

    /**
     * Copies properties from one Bean to another Bean.
     *
     * @param src The source Bean. Must not be {@literal null}.

    // manually add elements to avoid expansion
    // 1/3 null keys, 1/3 null values
    int originalCount = 1024;
    InternalEntry<Object, Object, ?> entry = null;
    for (int i = 0; i < originalCount; i++) {
      Object key = new Object();
      Object value = (i % 3 == 0) ? null : new Object();
      int hash = map.hash(key);
      if (i % 3 == 1) {
        key = null;
      }