* and wrongly believes that its exception is new (leading it to logging it when it shouldn't)
     *
     * Our solution is for threads to CAS seenExceptions from null to a Set populated with _the
     * initial exception_, no matter which thread does the work. This ensures that seenExceptions
     * always contains not just the current thread's exception but also the initial thread's.
     */

            task = null;
          }
        }
      } finally {
        // Ensure that if the thread was interrupted at all while processing the task queue, it
        // is returned to the delegate Executor interrupted so that it may handle the
        // interruption if it likes.
        if (interruptedDuringTask) {
          Thread.currentThread().interrupt();
        }
      }
    }

    @SuppressWarnings("GuardedBy")

    /*
     * TODO(cpovirk): Should whenAllComplete().call*() log errors, too? Currently, it doesn't call
     * handleException() at all.
     */
    if (throwable instanceof Error) {
      /*
       * TODO(cpovirk): Do we really want to log this if we called setException(throwable) and it
       * returned true? This was intentional (CL 46470009), but it seems odd compared to how we
       * normally handle Error.
       *

      Iterable<? extends T> iterable, Comparator<T> comparator) {
    checkNotNull(comparator);
    Iterator<? extends T> it = iterable.iterator();
    if (it.hasNext()) {
      T prev = it.next();
      while (it.hasNext()) {
        T next = it.next();
        if (comparator.compare(prev, next) >= 0) {
          return false;
        }
        prev = next;
      }
    }

    private boolean foundAndRemovedExactReference(Iterable<E> elements, E target) {
      for (Iterator<E> it = elements.iterator(); it.hasNext(); ) {
        E element = it.next();
        if (element == target) {
          it.remove();
          return true;
        }
      }
      return false;
    }

    propagateIfInstanceOf(throwable, declaredType1);
    propagateIfPossible(throwable, declaredType2);
  }

  /**
   * Propagates {@code throwable} as-is if it is an instance of {@link RuntimeException} or {@link
   * Error}, or else as a last resort, wraps it in a {@code RuntimeException} and then propagates.
   *
   * <p>This method always throws an exception. The {@code RuntimeException} return type allows

    propagateIfInstanceOf(throwable, declaredType1);
    propagateIfPossible(throwable, declaredType2);
  }

  /**
   * Propagates {@code throwable} as-is if it is an instance of {@link RuntimeException} or {@link
   * Error}, or else as a last resort, wraps it in a {@code RuntimeException} and then propagates.
   *
   * <p>This method always throws an exception. The {@code RuntimeException} return type allows

     * it returns a subclass of Joiner that overrides this method to tolerate null inputs.
     *
     * Unfortunately, we don't distinguish between these two cases in our public API: Joiner.on(...)
     * and Joiner.on(...).useForNull(...) both declare the same return type: plain Joiner. To ensure
     * that users *can* pass null arguments to Joiner, we annotate it as if it always tolerates null

   * is complete. It does so by using daemon threads and adding a shutdown hook to wait for their
   * completion.
   *
   * <p>This is mainly for fixed thread pools. See {@link Executors#newFixedThreadPool(int)}.
   *
   * @param executor the executor to modify to make sure it exits when the application is finished

 * thought of as overkill; however, it's difficult to determine which proper subset of this massive
 * set would be sufficient to expose any possible bug. Brute force is simpler.
 *
 * <p>To use this class the concrete subclass must implement the {@link
 * IteratorTester#newTargetIterator()} method. This is because it's impossible to test an Iterator