return 5;
          }
        };

    Function<Number, Integer> intValueFunction =
        new Function<Number, Integer>() {
          @Override
          public Integer apply(Number x) {
            return x.intValue();
          }
        };

    Supplier<Integer> squareSupplier = Suppliers.compose(intValueFunction, fiveSupplier);

     */
    fun cookieJar(cookieJar: CookieJar) =
      apply {
        this.cookieJar = cookieJar
      }

    /** Sets the response cache to be used to read and write cached responses. */
    fun cache(cache: Cache?) =
      apply {
        this.cache = cache
      }

    internal fun taskRunner(taskRunner: TaskRunner) =
      apply {
        this.taskRunner = taskRunner
      }

    /**

    T instance = generator.newFreshProxy(interfaceType);
    new EqualsTester()
        .addEqualityGroup(wrapperFunction.apply(instance), wrapperFunction.apply(instance))
        .addEqualityGroup(wrapperFunction.apply(generator.newFreshProxy(interfaceType)))
        // TODO: add an overload to EqualsTester to print custom error message?
        .testEquals();
  }

      val trustManager =
        TrustManagerFactory
          .getInstance(TrustManagerFactory.getDefaultAlgorithm())
          .apply {
            init(null as KeyStore?)
          }.trustManagers
          .first() as X509TrustManager

      val sslContext =
        Platform.get().newSSLContext().apply {
          // TODO remove most of this code after https://github.com/bcgit/bc-java/issues/686

    }

    fun client(client: OkHttpClient) =
      apply {
        this.client = client
      }

    fun url(url: HttpUrl) =
      apply {
        this.url = url
      }

    fun includeIPv6(includeIPv6: Boolean) =
      apply {
        this.includeIPv6 = includeIPv6
      }

    fun post(post: Boolean) =
      apply {
        this.post = post
      }

    socketFactory[ipv6] = server1.socketAddress
    socketFactory[ipv4] = server2.socketAddress

    client =
      client
        .newBuilder()
        .fastFallback(false)
        .apply {
          retryOnConnectionFailure = false
        }.build()

    executeSynchronously(request)
      .assertFailureMatches("stream was reset: REFUSED_STREAM")

    assertTrue(equalTo1.apply("1"));
    assertFalse(equalTo1.apply("2"));
    assertFalse(equalTo1.apply(null));
    Predicate<@Nullable Object> isNull = Equivalence.equals().equivalentTo(null);
    assertFalse(isNull.apply("1"));
    assertFalse(isNull.apply("2"));
    assertTrue(isNull.apply(null));

    new EqualsTester()

    assertTrue(equalTo1.apply("1"));
    assertFalse(equalTo1.apply("2"));
    assertFalse(equalTo1.apply(null));
    Predicate<@Nullable Object> isNull = Equivalence.equals().equivalentTo(null);
    assertFalse(isNull.apply("1"));
    assertFalse(isNull.apply("2"));
    assertTrue(isNull.apply(null));

    new EqualsTester()

      value: String,
    ) = apply {
      headers.add(name, value)
    }

    /** Removes all headers named [name] on this builder. */
    open fun removeHeader(name: String) =
      apply {
        headers.removeAll(name)
      }

    /** Removes all headers on this builder and adds [headers]. */
    open fun headers(headers: Headers) =
      apply {
        this.headers = headers.newBuilder()

  public boolean containsKey(@Nullable Object key) {
    if (unfiltered.containsKey(key)) {
      @SuppressWarnings("unchecked") // k is equal to a K, if not one itself
      K k = (K) key;
      return keyPredicate.apply(k);
    }
    return false;
  }

  @Override
  public Collection<V> removeAll(@Nullable Object key) {
    return containsKey(key) ? unfiltered.removeAll(key) : unmodifiableEmptyCollection();
  }