private TimeoutFutureException(String message) {
      super(message);
    }

    @Override
    public synchronized Throwable fillInStackTrace() {
      setStackTrace(new StackTraceElement[0]);
      return this; // no stack trace, wouldn't be useful anyway
    }
  }

  @Override
  @CheckForNull
  protected String pendingToString() {

    // Now we test a property that holds only for the lazy implementation.

    if (!lazyStackTraceIsLazy()) {
      return;
    }

    e.setStackTrace(new StackTraceElement[0]);
    assertThat(lazyStackTrace(e)).containsExactly((Object[]) originalStackTrace).inOrder();
  }

  @J2ktIncompatible
  @GwtIncompatible // lazyStackTrace

    // Now we test a property that holds only for the lazy implementation.

    if (!lazyStackTraceIsLazy()) {
      return;
    }

    e.setStackTrace(new StackTraceElement[0]);
    assertThat(lazyStackTrace(e)).containsExactly((Object[]) originalStackTrace).inOrder();
  }

  @J2ktIncompatible
  @GwtIncompatible // lazyStackTrace

      throw e;
    }
    if (combineStackTraces) {
      StackTraceElement[] combined =
          ObjectArrays.concat(cause.getStackTrace(), e.getStackTrace(), StackTraceElement.class);
      cause.setStackTrace(combined);
    }
    if (cause instanceof Exception) {
      throw (Exception) cause;
    }
    if (cause instanceof Error) {
      throw (Error) cause;
    }

   *       1/stackSize}).
   * </ul>
   *
   * <p>Note: The special implementation does not respect calls to {@link Throwable#setStackTrace
   * throwable.setStackTrace}. Instead, it always reflects the original stack trace from the
   * exception's creation.
   *
   * @since 19.0

   *       1/stackSize}).
   * </ul>
   *
   * <p>Note: The special implementation does not respect calls to {@link Throwable#setStackTrace
   * throwable.setStackTrace}. Instead, it always reflects the original stack trace from the
   * exception's creation.
   *
   * @since 19.0

          // For pre-populated disallowedPriorLocks edges, omit the stack trace.
          setStackTrace(EMPTY_STACK_TRACE);
          break;
        }
        if (!EXCLUDED_CLASS_NAMES.contains(origStackTrace[i].getClassName())) {
          setStackTrace(Arrays.copyOfRange(origStackTrace, i, n));
          break;
        }
      }
    }
  }

  /**

   * snapshot of the state and therefore it can be used to answer simple queries without needing to
   * grab a lock.
   */
  // @Immutable except that Throwable is mutable (initCause(), setStackTrace(), mutable subclasses).
  private static final class StateSnapshot {
    /**
     * The internal state, which equals external state unless shutdownWhenStartupFinishes is true.
     */
    final State state;