delegate.clear();
    }

    @Override
    public Collection<V> values() {
      assertTrue(Thread.holdsLock(mutex));
      /* TODO: verify that the Collection is also synchronized? */
      return delegate.values();
    }

    @Override
    public Set<Cell<R, C, V>> cellSet() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.cellSet();
    }

    @Override

         * @param groups Array of group names.
         */
        public synchronized void setGroups(final String[] groups) {
            this.groups = groups;
        }

        /**
         * Sets the user's role assignments.
         * @param roles Array of role names.
         */
        public synchronized void setRoles(final String[] roles) {
            this.roles = roles;
        }

        executionList.execute();
      }
      return result;
    }

    /**
     * Following the contract of {@link AbstractQueuedSynchronizer} we create a private subclass to
     * hold the synchronizer. This synchronizer is used to implement the blocking and waiting calls
     * as well as to handle state changes in a thread-safe manner. The current state of the future

     *
     * @param factory The URL stream handler factory.
     */
    public static void setURLStreamHandlerFactory(final URLStreamHandlerFactory factory) {
        synchronized (PROTOCOL_HANDLERS) {
            if (Handler.factory != null) {
                throw new IllegalStateException("URLStreamHandlerFactory already set.");
            }
            PROTOCOL_HANDLERS.clear();

            return hashAlgorithm;
        }

        public byte[] getCurrentHash() {
            synchronized (hashLock) {
                return currentHash.clone();
            }
        }

        public void updateHash(byte[] newHash) {
            synchronized (hashLock) {
                if (newHash != null && newHash.length == currentHash.length) {

     *
     * @param props the properties to use for initialization
     * @throws CIFSException if the singleton context is already initialized or there is an error during initialization
     */
    public static synchronized final void init(final Properties props) throws CIFSException {
        if (INSTANCE != null) {
            throw new CIFSException("Singleton context is already initialized");
        }

    }

    /**
     * Adds a key-value pair to the information map.
     * Initializes the info map as a synchronized LinkedHashMap if it doesn't exist.
     *
     * @param key the parameter key to store
     * @param value the parameter value to store
     */
    public synchronized void putToInfoMap(final String key, final String value) {
        if (infoMap == null) {

    Multimap<K, V> multimap = synchronizedMultimap(HashMultimap.<K, V>create());
    Collection<V> values = multimap.get(key); // Needn't be in synchronized block
    synchronized (multimap) { // Synchronizing on multimap, not values!
      Iterator<V> i = values.iterator(); // Must be in synchronized block
      while (i.hasNext()) {
        foo(i.next());
      }
    }
  }

  private static void foo(Object unused) {}

      delegate.clear();
    }

    @Override
    public Collection<V> values() {
      assertTrue(Thread.holdsLock(mutex));
      /* TODO: verify that the Collection is also synchronized? */
      return delegate.values();
    }

    @Override
    public Set<Cell<R, C, V>> cellSet() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.cellSet();
    }

    @Override

        lock = new Object();
    }

    @Override
    public int read() throws IOException {
        int result = -1;

        synchronized (lock) {
            try {
                while (used == 0) {
                    lock.wait();
                }
            } catch (final InterruptedException ie) {