// that's handled by the log check that catches RuntimeExceptions in the queue worker.
        if (!(t instanceof RejectedExecutionException) || removed) {
          throw t;
        }
      }
      return;
    }

    /*
     * This is an unsynchronized read! After the read, the function returns immediately or acquires

    return true;
  }

  /**
   * Checks all the properties that should always hold of a map. Also calls {@link
   * #assertMoreInvariants} to check invariants that are peculiar to specific implementations.
   *
   * @see #assertMoreInvariants
   * @param map the map to check.
   */
  protected final void assertInvariants(Map<K, V> map) {
    Set<K> keySet = map.keySet();
    Collection<V> valueCollection = map.values();

   * need to be signalled because it is not known which if any of them have waiters (and hasWaiters
   * can't be used reliably because of a check-then-act race). With our Monitor guards, we only
   * signal the first active guard that is satisfied. But the corresponding thread may have already

    AvlNode<E> root = rootReference.get();
    if (root == null) {
      return null;
    }
    AvlNode<E> node;
    if (range.hasLowerBound()) {
      // The cast is safe because of the hasLowerBound check.
      E endpoint = uncheckedCastNullableTToT(range.getLowerEndpoint());
      node = root.ceiling(comparator(), endpoint);
      if (node == null) {
        return null;
      }

    }
  }

  /*
   * Whenever an implementation uses `instanceof` on a parameter instance, the test has to know that
   * (so much for "black box") and try instances that both do and don't pass the check. The "don't"
   * half of that is more awkward to arrange...
   */
  private static <T> Iterable<T> iterable(final Collection<T> collection) {
    // return collection::iterator;
    return new Iterable<T>() {

    }
  }

  /*
   * Whenever an implementation uses `instanceof` on a parameter instance, the test has to know that
   * (so much for "black box") and try instances that both do and don't pass the check. The "don't"
   * half of that is more awkward to arrange...
   */
  private static <T> Iterable<T> iterable(final Collection<T> collection) {
    // return collection::iterator;
    return new Iterable<T>() {

 *       scalability or other performance factors (see the separate "jtreg" tests for a set intended
 *       to check these for the most central aspects of functionality.) So, most tests use the
 *       smallest sensible numbers of threads, collection sizes, etc needed to check basic
 *       conformance.
 *   <li>The test classes currently do not declare inclusion in any particular package to simplify

     * bad. We do the leadingZeros check to avoid the division below if at all possible.
     *
     * Otherwise, if b == Long.MIN_VALUE, then the only allowed values of a are 0 and 1. We take
     * care of all a < 0 with their own check, because in particular, the case a == -1 will
     * incorrectly pass the division check below.
     *
     * In all other cases, we check that either a is 0 or the result is consistent with division.

    /*
     * Safe because all we do is remove values for the key, not add them. (If we wanted to make sure
     * to call getCopy and removeAllNodes only with a true K, then we could check containsKey first.
     * But that check wouldn't eliminate the warnings.)
     */
    @SuppressWarnings({"unchecked", "nullness"})
    K castKey = (K) key;
    List<V> oldValues = getCopy(castKey);
    removeAllNodes(castKey);

    try {
      Hashing.hmacMd5(badKey);
      fail();
    } catch (IllegalArgumentException expected) {
    } catch (NullPointerException toleratedOnAndroid) {
      // TODO(cpovirk): In an ideal world, we'd check here that we're running on Android.
    }
  }

  public void testEmptyInputs() throws Exception {
    String knownOutput = "8cbf764cbe2e4623d99a41354adfd390";

    Mac mac = Mac.getInstance("HmacMD5");