* this is no worse than what FutureTask does in that situation. Additionally, because the
     * Future was cancelled, its listeners have been run, so its consumers will not hang.
     *
     * Contrast this to the situation we have if setResult() throws, a situation described below.
     */
    I sourceResult;
    try {
      sourceResult = getDone(localInputFuture);

    long hangDelayMillis =
        (expectedOutcome == Outcome.HANG)
            ? EXPECTED_HANG_DELAY_MILLIS
            : UNEXPECTED_HANG_DELAY_MILLIS;
    boolean hung =
        !awaitUninterruptibly(callCompletedLatch, hangDelayMillis, TimeUnit.MILLISECONDS);
    if (hung) {
      assertEquals(expectedOutcome, Outcome.HANG);
    } else {
      assertNull(task.get(UNEXPECTED_HANG_DELAY_MILLIS, TimeUnit.MILLISECONDS));
    }
  }

    long hangDelayMillis =
        (expectedOutcome == Outcome.HANG)
            ? EXPECTED_HANG_DELAY_MILLIS
            : UNEXPECTED_HANG_DELAY_MILLIS;
    boolean hung =
        !awaitUninterruptibly(callCompletedLatch, hangDelayMillis, TimeUnit.MILLISECONDS);
    if (hung) {
      assertEquals(expectedOutcome, Outcome.HANG);
    } else {
      assertNull(task.get(UNEXPECTED_HANG_DELAY_MILLIS, TimeUnit.MILLISECONDS));
    }
  }

   * @param terminationTimeout how long to wait for the executor to finish before terminating the
   *     JVM
   * @param timeUnit unit of time for the time parameter
   * @return an unmodifiable version of the input which will not hang the JVM
   */
  @J2ktIncompatible
  @GwtIncompatible // TODO
  @SuppressWarnings("GoodTime") // should accept a java.time.Duration
  public static ExecutorService getExitingExecutorService(