}

    /**
     * Waits for the crawling process to terminate indefinitely.
     */
    public void awaitTermination() {
        awaitTermination(0);
    }

    /**
     * Waits for the crawling process to terminate for a specified duration.
     * @param millis The maximum time to wait in milliseconds. A value of 0 means wait indefinitely.
     */
    public void awaitTermination(final long millis) {

   *
   * <p>If, at any step of the process, the calling thread is interrupted, the method calls {@link
   * ExecutorService#shutdownNow()} and returns.
   *
   * <p>For a version of this method that waits <i>indefinitely</i>, use {@link
   * ExecutorService#close}.
   *
   * @param service the {@code ExecutorService} to shut down
   * @param timeout the maximum time to wait for the {@code ExecutorService} to terminate

      return ((Set<?>) iterable).contains(element) ? 1 : 0;
    }
    return Iterators.frequency(iterable.iterator(), element);
  }

  /**
   * Returns an iterable whose iterators cycle indefinitely over the elements of {@code iterable}.
   *
   * <p>That iterator supports {@code remove()} if {@code iterable.iterator()} does. After {@code

      // though that isn't currently publicly documented.
      count++;
    }
    return count;
  }

  /**
   * Returns an iterator that cycles indefinitely over the elements of {@code iterable}.
   *
   * <p>The returned iterator supports {@code remove()} if the provided iterator does. After {@code

 * that provide readers that are:
 *
 * <ul>
 *   <li><b>Finite:</b> Many operations, such as {@link #length()} and {@link #read()}, will either
 *       block indefinitely or fail if the source creates an infinite reader.
 *   <li><b>Non-destructive:</b> A <i>destructive</i> reader will consume or otherwise alter the

 * that provide readers that are:
 *
 * <ul>
 *   <li><b>Finite:</b> Many operations, such as {@link #length()} and {@link #read()}, will either
 *       block indefinitely or fail if the source creates an infinite reader.
 *   <li><b>Non-destructive:</b> A <i>destructive</i> reader will consume or otherwise alter the

      return ((Set<?>) iterable).contains(element) ? 1 : 0;
    }
    return Iterators.frequency(iterable.iterator(), element);
  }

  /**
   * Returns an iterable whose iterators cycle indefinitely over the elements of {@code iterable}.
   *
   * <p>That iterator supports {@code remove()} if {@code iterable.iterator()} does. After {@code

    }

    // N.B. Draining the queue is only necessary to ensure that we don't accumulate empty references
    // in the array. We could skip this if we decide we don't care about holding on to Reference
    // objects indefinitely.
    private void drainQueue() {
      Reference<? extends L> ref;
      while ((ref = queue.poll()) != null) {
        // We only ever register ArrayReferences with the queue so this is always safe.

 * that provide streams that are:
 *
 * <ul>
 *   <li><b>Finite:</b> Many operations, such as {@link #size()} and {@link #read()}, will either
 *       block indefinitely or fail if the source creates an infinite stream.
 *   <li><b>Non-destructive:</b> A <i>destructive</i> stream will consume or otherwise alter the

but that should be extremely rare.

GODEBUG settings added for compatibility will be maintained
for a minimum of two years (four Go releases).
Some, such as `http2client` and `http2server`,
will be maintained much longer, even indefinitely.

When possible, each GODEBUG setting has an associated
[runtime/metrics](/pkg/runtime/metrics/) counter
named `/godebug/non-default-behavior/<name>:events`
that counts the number of times a particular program's