* dependency on those interfaces.
   */
  private class AlpnProvider(
    /** This peer's supported protocols. */
    private val protocols: List<String>,
  ) : InvocationHandler {
    /** Set when remote peer notifies ALPN is unsupported. */
    var unsupported: Boolean = false

    /** The protocol the server selected. */
    var selected: String? = null

    @Throws(Throwable::class)

  ) = throw CertificateException("Unsupported operation")

  override fun checkClientTrusted(
    chain: Array<out X509Certificate>,
    authType: String?,
  ) = throw CertificateException("Unsupported operation")

  override fun checkClientTrusted(
    chain: Array<out X509Certificate>,
    authType: String,
    engine: SSLEngine?,
  ) = throw CertificateException("Unsupported operation")

    assertThrows(NullPointerException.class, () -> getMap().putIfAbsent(null, v3()));
    expectUnchanged();
    expectNullKeyMissingWhenNullKeysUnsupported(
        "Should not contain null key after unsupported putIfAbsent(null, value)");
  }

  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_VALUES)
  public void testPutIfAbsent_nullValueUnsupportedAndKeyAbsent() {

    assertThrows(NullPointerException.class, () -> getMap().putIfAbsent(null, v3()));
    expectUnchanged();
    expectNullKeyMissingWhenNullKeysUnsupported(
        "Should not contain null key after unsupported putIfAbsent(null, value)");
  }

  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_VALUES)
  public void testPutIfAbsent_nullValueUnsupported() {

    assertThrows(NullPointerException.class, () -> getMap().putIfAbsent(null, v3()));
    expectUnchanged();
    expectNullKeyMissingWhenNullKeysUnsupported(
        "Should not contain null key after unsupported putIfAbsent(null, value)");
  }

  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_VALUES)
  public void testPutIfAbsent_nullValueUnsupported() {

    assertThrows(NullPointerException.class, () -> getMap().putIfAbsent(null, v3()));
    expectUnchanged();
    expectNullKeyMissingWhenNullKeysUnsupported(
        "Should not contain null key after unsupported putIfAbsent(null, value)");
  }

  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_VALUES)
  public void testPutIfAbsent_nullValueUnsupportedAndKeyAbsent() {

 * Object#hashCode} and {@link Object#toString}. For example:
 *
 * <pre>
 * class Unsupported extends AbstractInvocationHandler {
 *   protected Object handleInvocation(Object proxy, Method method, Object[] args) {
 *     throw new UnsupportedOperationException();
 *   }
 * }
 *
 * CharSequence unsupported = Reflection.newProxy(CharSequence.class, new Unsupported());
 * </pre>
 *
 * @author Ben Yu
 * @since 12.0
 */

  protected UnmodifiableListIterator() {}

  /**
   * Guaranteed to throw an exception and leave the underlying data unmodified.
   *
   * @throws UnsupportedOperationException always
   * @deprecated Unsupported operation.
   */
  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  public final void add(@ParametricNullness E e) {
    throw new UnsupportedOperationException();
  }

      TypeToken<@NonNull T> type, @ParametricNullness T value) {
    return this.<T>trustedPut(type.rejectTypeVariables(), value);
  }

  /**
   * Not supported. Use {@link #putInstance} instead.
   *
   * @deprecated unsupported operation
   * @throws UnsupportedOperationException always
   */
  @CanIgnoreReturnValue
  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")

      TypeToken<@NonNull T> type, @ParametricNullness T value) {
    return this.<T>trustedPut(type.rejectTypeVariables(), value);
  }

  /**
   * Not supported. Use {@link #putInstance} instead.
   *
   * @deprecated unsupported operation
   * @throws UnsupportedOperationException always
   */
  @CanIgnoreReturnValue
  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")