* proxy server can issue an auth challenge and then close the connection.
   *
   * @return the next plan to attempt, or null if no further attempt should be made either because
   *     we've successfully connected or because no further attempts should be made.
   */
  @Throws(IOException::class)
  internal fun connectTunnel(): ConnectResult {
    val nextTunnelRequest =
      createTunnel()

 * family. <b>Avoid</b> creating a mock or stub {@code Future}. Mock and stub implementations are
 * fragile because they assume that only certain methods will be called and because they often
 * implement subtleties of the API improperly.
 *
 * <p><b>Custom implementation</b>: Avoid implementing {@code ListenableFuture} from scratch. If you

 * family. <b>Avoid</b> creating a mock or stub {@code Future}. Mock and stub implementations are
 * fragile because they assume that only certain methods will be called and because they often
 * implement subtleties of the API improperly.
 *
 * <p><b>Custom implementation</b>: Avoid implementing {@code ListenableFuture} from scratch. If you

  public void testPutStringWithLowSurrogate() {
    // we pad because the dummy hash function we use to test this, merely copies the input into
    // the output, so the input must be at least 32 bits, since the output has to be that long
    assertPutString(new char[] {'p', HashTestUtils.randomLowSurrogate(new Random())});
  }

  public void testPutStringWithHighSurrogate() {

    } else if (bufferSize < k) {
      buffer[bufferSize++] = elem;
      // uncheckedCastNullableTToT is safe because bufferSize > 0.
      if (comparator.compare(elem, uncheckedCastNullableTToT(threshold)) > 0) {
        threshold = elem;
      }
      // uncheckedCastNullableTToT is safe because bufferSize > 0.
    } else if (comparator.compare(elem, uncheckedCastNullableTToT(threshold)) < 0) {

        } catch (RuntimeException e) {
            // TODO Hack to make the cycle detection the same for the new graph builder
            if (e.getCause() instanceof ProjectCycleException) {
                result = addExceptionToResult(new DefaultMavenExecutionResult(), e.getCause());
            } else {
                result = addExceptionToResult(

        new AbstractFuture<Object>() {
          @Override
          public String pendingToString() {
            return "cause=[Because this test isn't done]";
          }
        };
    assertThat(testFuture.toString())
        .matches(
            "[^\\[]+\\[status=PENDING, info=\\[cause=\\[Because this test isn't done\\]\\]\\]");
    TimeoutException e = assertThrows(TimeoutException.class, () -> testFuture.get(1, NANOSECONDS));

      if (node.previousSibling == null) {
        // requireNonNull is safe because we checked that not *both* siblings were null.
        keyList.head = requireNonNull(node.nextSibling);
      } else {
        node.previousSibling.nextSibling = node.nextSibling;
      }

      if (node.nextSibling == null) {
        // requireNonNull is safe because we checked that not *both* siblings were null.

     * message}.
     */
    @Override
    public String getMessage() {
      // requireNonNull is safe because ExampleStackTrace sets a non-null message.
      StringBuilder message = new StringBuilder(requireNonNull(super.getMessage()));
      for (Throwable t = conflictingStackTrace; t != null; t = t.getCause()) {
        message.append(", ").append(t.getMessage());
      }
      return message.toString();
    }
  }

 * Contrast the method above to:
 *
 * <ul>
 *   <li>methods whose return type is a type variable but which can never return {@code null},
 *       typically because the type forbids nullable type arguments: For example, {@code
 *       ImmutableList.get} returns {@code E}, but that value is never {@code null}. (Accordingly,