@Deprecated
  public static <E extends @Nullable Object> Set<E> newSetFromMap(
      Map<E, Boolean> map) {
    return Collections.newSetFromMap(map);
  }

  /**
   * An unmodifiable view of a set which may be backed by other sets; this view will change as the
   * backing sets do. Contains methods to copy the data into a new set which will then remain

    /**
     * Get active resource information
     *
     * @return set of active resource descriptions
     */
    public Set<String> getActiveResources() {
        Set<String> result = Collections.newSetFromMap(new ConcurrentHashMap<>());

        for (ResourceHolder holder : activeResources.values()) {
            if (!holder.closed && holder.isAlive()) {

       * UnsignedBytesBenchmark. TODO(cpovirk): benchmark this
       */
      /*
       * A CopyOnWriteArraySet<WeakReference> is faster than a newSetFromMap of a MapMaker map with
       * weakKeys() and concurrencyLevel(1), even up to at least 12 cached exception types.
       */
      private static final Set<WeakReference<Class<? extends Exception>>> validClasses =

       * UnsignedBytesBenchmark. TODO(cpovirk): benchmark this
       */
      /*
       * A CopyOnWriteArraySet<WeakReference> is faster than a newSetFromMap of a MapMaker map with
       * weakKeys() and concurrencyLevel(1), even up to at least 12 cached exception types.
       */
      private static final Set<WeakReference<Class<? extends Exception>>> validClasses =