@MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_VALUES)
  public void testAddNullValueUnsupported() {
    Collection<V> result = multimap().asMap().get(k0());
    assertThrows(NullPointerException.class, () -> result.add(null));
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(SUPPORTS_PUT)
  public void testPropagatesAddToMultimap() {

    @DisplayName("writeParametersWireFormat throws on null path")
    void testNullPath() {
        Trans2GetDfsReferral cmd = new Trans2GetDfsReferral(null);
        byte[] buffer = new byte[10];
        assertThrows(NullPointerException.class, () -> cmd.writeParametersWireFormat(buffer, 0));
    }

    @Nested
    @DisplayName("read methods are no‑ops")
    class ReadMethods {

        assertNotNull(result);
        assertEquals("", result);
    }

    @Test
    @DisplayName("Should handle null byte array")
    void testToHexStringNull() {
        // When/Then
        assertThrows(NullPointerException.class, () -> {
            Hexdump.toHexString(null);
        });
    }

    @Test
    @DisplayName("Should convert byte array to hex string with offset and length")
    void testHexdumpWithOffset() {

        assertEquals(longMessage, exception.getMessage());
    }

    public void test_multiLevelExceptionChain() {
        // Test multi-level exception chain
        Throwable level3 = new NullPointerException("Null value");
        Throwable level2 = new IllegalStateException("Invalid state", level3);
        Throwable level1 = new RuntimeException("Runtime error", level2);

    val next = copy(index = index + 1, request = request)
    val interceptor = interceptors[index]

    @Suppress("USELESS_ELVIS")
    val response =
      interceptor.intercept(next) ?: throw NullPointerException(
        "interceptor $interceptor returned null",
      )

    if (exchange != null) {
      check(index + 1 >= interceptors.size || next.calls == 1) {

      throw AssertionError(e)
    } catch (e: InvocationTargetException) {
      // https://github.com/square/okhttp/issues/5587
      val cause = e.cause
      when {
        cause is NullPointerException && cause.message == "ssl == null" -> null
        else -> throw AssertionError(e)
      }
    }
  }

  companion object {
    val playProviderFactory: DeferredSocketAdapter.Factory =

    // Assert that escapers throw null pointer exceptions.
    try {
      escaper.escape((String) null);
      Assert.fail("exception not thrown when escaping a null string");
    } catch (NullPointerException e) {
      // pass
    }
  }

  /**
   * Asserts that an escaper escapes the given character into the expected string.
   *
   * @param escaper the non-null escaper to test

 */
@SuppressWarnings("rawtypes") // maybe avoidable if we rework the whole package?
@GwtCompatible
public enum CollectionFeature implements Feature<Collection> {
  /**
   * The collection must not throw {@code NullPointerException} on calls such as {@code
   * contains(null)} or {@code remove(null)}, but instead must return a simple {@code false}.
   */
  ALLOWS_NULL_QUERIES,
  ALLOWS_NULL_VALUES(ALLOWS_NULL_QUERIES),

  /**

    // Assert that escapers throw null pointer exceptions.
    try {
      escaper.escape((String) null);
      Assert.fail("exception not thrown when escaping a null string");
    } catch (NullPointerException e) {
      // pass
    }
  }

  /**
   * Asserts that an escaper escapes the given character into the expected string.
   *
   * @param escaper the non-null escaper to test

     *
     * @param password the password to hash
     * @return nt password hash
     */
    public static byte[] getNTHash(final String password) {
        if (password == null) {
            throw new NullPointerException("Password parameter is required");
        }
        final MessageDigest md4 = Crypto.getMD4();
        md4.update(Strings.getUNIBytes(password));
        return md4.digest();
    }

    /**