// the slower pointer, then there's a loop.
    Throwable slowPointer = throwable;
    boolean advanceSlowPointer = false;

    Throwable cause;
    while ((cause = throwable.getCause()) != null) {
      throwable = cause;
      causes.add(throwable);

      if (throwable == slowPointer) {

    // the slower pointer, then there's a loop.
    Throwable slowPointer = throwable;
    boolean advanceSlowPointer = false;

    Throwable cause;
    while ((cause = throwable.getCause()) != null) {
      throwable = cause;
      causes.add(throwable);

      if (throwable == slowPointer) {

    firstException = expected;
    // Second time should also fail, with a cached causal chain.
    expected = assertThrows(PotentialDeadlockException.class, () -> lockA.lock());
    checkMessage(expected, "LockB -> LockA", "LockA -> LockB");
    // The causal chain should be cached.
    assertSame(firstException.getCause(), expected.getCause());
    // lockA should work after lockB is released.

    firstException = expected;
    // Second time should also fail, with a cached causal chain.
    expected = assertThrows(PotentialDeadlockException.class, () -> lockA.lock());
    checkMessage(expected, "LockB -> LockA", "LockA -> LockB");
    // The causal chain should be cached.
    assertSame(firstException.getCause(), expected.getCause());
    // lockA should work after lockB is released.

      boolean completedWithFailure = setException(throwable);
      if (!completedWithFailure) {
        // Go up the causal chain to see if we've already seen this cause; if we have, even if
        // it's wrapped by a different exception, don't log it.
        boolean firstTimeSeeingThisException = addCausalChain(getOrInitSeenExceptions(), throwable);

   * of {@code ExampleStackTrace} instances to illustrate the cycle, e.g.
   *
   * <pre>
   * com....PotentialDeadlockException: Potential Deadlock from LockC -&gt; ReadWriteA
   *   at ...
   *   at ...
   * Caused by: com...ExampleStackTrace: LockB -&gt; LockC
   *   at ...
   *   at ...
   * Caused by: com...ExampleStackTrace: ReadWriteA -&gt; LockB

                Throwable cause = exception.getCause();

                if (cause instanceof PluginContainerException) {
                    Throwable cause2 = cause.getCause();

                    if (cause2 instanceof NoClassDefFoundError) {
                        String message = cause2.getMessage();

  }

  /**
   * Asserts that a prior call that had caused this thread to block or wait has since returned
   * normally.
   */
  public void assertPriorCallReturns(@Nullable String methodName) throws Exception {
    assertEquals(null, getResponse(methodName).getResult());
  }

  /**
   * Asserts that a prior call that had caused this thread to block or wait has since returned the
   * expected boolean value.

    assertSame(cause, Throwables.getRootCause(exception));
  }

  public void testGetRootCause_Loop() {
    Exception cause = new Exception();
    Exception exception = new Exception(cause);
    cause.initCause(exception);
    try {
      Throwables.getRootCause(cause);
      fail("Should have throw IAE");
    } catch (IllegalArgumentException expected) {

    assertSame(cause, Throwables.getRootCause(exception));
  }

  public void testGetRootCause_Loop() {
    Exception cause = new Exception();
    Exception exception = new Exception(cause);
    cause.initCause(exception);
    try {
      Throwables.getRootCause(cause);
      fail("Should have throw IAE");
    } catch (IllegalArgumentException expected) {