*
   * <p>A failing {@link TearDown} may or may not fail a tl4j test, depending on the version of
   * JUnit test case you are running under. To avoid failing in the face of an exception regardless
   * of JUnit version, implement a {@link SloppyTearDown} instead.
   *
   * <p>tl4j details: For backwards compatibility, {@code junit3.TearDownTestCase} currently does

on:  `But why did they live at the bottom of a well?'

  `Take some more tea,' the March Hare said to Alice, very
earnestly.

  `I've had nothing yet,' Alice replied in an offended tone, `so
I can't take more.'

  `You mean you can't take LESS,' said the Hatter:  `it's very
easy to take MORE than nothing.'

  `Nobody asked YOUR opinion,' said Alice.

    assertThrows(IllegalArgumentException.class, () -> multiset.add(KEY, COUNT_TO_ADD));
  }

  /**
   * Simulate some of the races that can happen on add. We can't easily simulate the race that
   * happens when an {@link AtomicInteger#compareAndSet} fails, but we can simulate the case where
   * the putIfAbsent returns a non-null value, and the case where the replace() of an observed zero
   * fails.
   */

   *
   * <p>A failing {@link TearDown} may or may not fail a tl4j test, depending on the version of
   * JUnit test case you are running under. To avoid failing in the face of an exception regardless
   * of JUnit version, implement a {@link SloppyTearDown} instead.
   *
   * <p>tl4j details: For backwards compatibility, {@code junit3.TearDownTestCase} currently does

 * this structure is never mutated, it provides a thread-safe view of the backing map.
 *
 * <p>The {@link MapIteratorCache} assumes ownership of the backing map, and cannot guarantee
 * correctness in the face of external mutations to the backing map. As such, it is <b>strongly</b>
 * recommended that the caller does not persist a reference to the backing map (unless the backing
 * map is immutable).
 *

      long nanos = expirationNanos;
      long now = System.nanoTime();
      if (nanos == 0 || now - nanos >= 0) {
        synchronized (this) {
          if (nanos == expirationNanos) { // recheck for lost race
            T t = delegate.get();
            value = t;
            nanos = now + durationNanos;
            // In the very unlikely event that nanos is 0, set it to 1;

on:  `But why did they live at the bottom of a well?'

  `Take some more tea,' the March Hare said to Alice, very
earnestly.

  `I've had nothing yet,' Alice replied in an offended tone, `so
I can't take more.'

  `You mean you can't take LESS,' said the Hatter:  `it's very
easy to take MORE than nothing.'

  `Nobody asked YOUR opinion,' said Alice.

        //
        // Note that there is a race condition here which can result in missing
        // a cyclic edge: it's possible for two threads to simultaneous find
        // "safe" edges which together form a cycle. Preventing this race
        // condition efficiently without _introducing_ deadlock is probably
        // tricky. For now, just accept the race condition---missing a warning

    return stringWriter.toString();
  }

  /**
   * Returns the stack trace of {@code throwable}, possibly providing slower iteration over the full
   * trace but faster iteration over parts of the trace. Here, "slower" and "faster" are defined in
   * comparison to the normal way to access the stack trace, {@link Throwable#getStackTrace()

    return stringWriter.toString();
  }

  /**
   * Returns the stack trace of {@code throwable}, possibly providing slower iteration over the full
   * trace but faster iteration over parts of the trace. Here, "slower" and "faster" are defined in
   * comparison to the normal way to access the stack trace, {@link Throwable#getStackTrace()