}
      // Recurse the edges.
      for (Entry<LockGraphNode, ExampleStackTrace> entry : allowedPriorLocks.entrySet()) {
        LockGraphNode preAcquiredLock = entry.getKey();
        found = preAcquiredLock.findPathTo(node, seen);
        if (found != null) {
          // One of this node's allowedPriorLocks found a path. Prepend an

    return new ByFunctionOrdering<>(function, this);
  }

  <T2 extends T> Ordering<Entry<T2, ?>> onKeys() {
    return onResultOf(Entry::getKey);
  }

  /**
   * Returns an ordering which first uses the ordering {@code this}, but which in the event of a
   * "tie", then delegates to {@code secondaryComparator}. For example, to sort a bug list first by

            if (fields != null) {
                final Map<String, Object> docMap = fields.entrySet()
                        .stream()
                        .collect(Collectors.toMap(Entry<String, DocumentField>::getKey, e -> (Object) e.getValue().getValues()));
                docMap.put(fessConfig.getIndexFieldId(), hit.getId());
                docMap.put(fessConfig.getIndexFieldVersion(), hit.getVersion());

      synchronized (this) {
        if (closed) {
          return;
        }
        closed = true;
      }
      for (Map.Entry<AutoCloseable, Executor> entry : entrySet()) {
        closeQuietly(entry.getKey(), entry.getValue());
      }
      clear();
      if (whenClosed != null) {
        whenClosed.countDown();
      }
    }

    void add(@Nullable AutoCloseable closeable, Executor executor) {