assertNotNull(nullBufferResponse);

        // But trying to read data should cause NullPointerException
        byte[] buffer = new byte[10];
        assertThrows(NullPointerException.class, () -> nullBufferResponse.readDataWireFormat(buffer, 0, 5));
    }

    @Test
    void testReadDataWireFormatWithNegativeLength() {

    /**
     * Test valueOf method with null
     */
    public void test_valueOf_null() {
        try {
            CrawlerStatus.valueOf(null);
            fail("Should throw NullPointerException for null value");
        } catch (NullPointerException e) {
            // Expected
        }
    }

    /**
     * Test name method
     */
    public void test_name() {

        DataStoreException withNPE = new DataStoreException("NPE Error", new NullPointerException("Null value"));
        DataStoreException withCustom = new DataStoreException("Custom Error", new FessSystemException("System error"));

        assertTrue(withIOException.getCause() instanceof java.io.IOException);
        assertTrue(withNPE.getCause() instanceof NullPointerException);
        assertTrue(withCustom.getCause() instanceof FessSystemException);

    Map<Class<? extends Number>, Number> nullKey = singletonMap(null, (Number) 1.0);
    assertThrows(NullPointerException.class, () -> ImmutableClassToInstanceMap.copyOf(nullKey));

    Map<? extends Class<? extends Number>, Number> nullValue = singletonMap(Number.class, null);
    assertThrows(NullPointerException.class, () -> ImmutableClassToInstanceMap.copyOf(nullValue));
  }

  public void testCopyOf_imap_empty() {

    }

    @Test
    @DisplayName("readParameterWordsWireFormat with null buffer - throws NullPointerException")
    void testReadParameterWordsWithNullBuffer() {
        assertThrows(NullPointerException.class, () -> response.readParameterWordsWireFormat(null, 0));
    }

    @Test

    @DisplayName("Reading with null array throws NullPointerException")
    void readNullArrayThrowsException() {
        // Create stream with valid message header and data
        byte[] data = new byte[] { 1 };
        InputStream in = new ByteArrayInputStream(concat(messageHeader(1), data));
        SocketInputStream sis = new SocketInputStream(in);

        // Should throw NullPointerException when reading with null array

     *
     * @throws NullPointerException if {@code key}, {@code values}, or any element in {@code values}
     *     is null. The builder is left in an invalid state.
     */
    @CanIgnoreReturnValue
    public Builder<K, V> putAll(K key, Iterable<? extends V> values) {
      if (key == null) {
        throw new NullPointerException("null key in entry: null=" + Iterables.toString(values));
      }

   * original interned instance was garbage-collected.
   *
   * <p><b>Warning:</b> do not use with mutable objects.
   *
   * @throws NullPointerException if {@code sample} is null
   */
  E intern(E sample);

    }

    /**
     * Associates all of {@code map's} keys and values in the built map. Duplicate keys are not
     * allowed, and will cause {@link #build} to fail.
     *
     * @throws NullPointerException if any key or value in {@code map} is null
     * @throws ClassCastException if any value is not an instance of the type specified by its key
     */
    @CanIgnoreReturnValue

    List<Object> list = new ArrayList<>(equalityGroup.length);
    for (int i = 0; i < equalityGroup.length; i++) {
      Object element = equalityGroup[i];
      if (element == null) {
        throw new NullPointerException("at index " + i);
      }
      list.add(element);
    }
    equalityGroups.add(list);
    return this;
  }

  /** Run tests on equals method, throwing a failure on an invalid test */