}

    @Override
    public ListIterator<E> listIterator(int index) {
      return delegate().listIterator(index); // manually synchronized
    }

    @Override
    public E remove(int index) {
      synchronized (mutex) {
        return delegate().remove(index);
      }
    }

    @Override
    public E set(int index, E element) {
      synchronized (mutex) {

    }

    @Override
    public ListIterator<E> listIterator(int index) {
      return delegate().listIterator(index); // manually synchronized
    }

    @Override
    public E remove(int index) {
      synchronized (mutex) {
        return delegate().remove(index);
      }
    }

    @Override
    public E set(int index, E element) {
      synchronized (mutex) {

            }
        }
    }

    protected synchronized void doDisconnect(final boolean hard) throws IOException {
        doDisconnect(hard, false);
    }

    @Override
    protected synchronized boolean doDisconnect(final boolean hard, final boolean inUse) throws IOException {

   * Multimap#replaceValues} methods return collections that aren't synchronized.
   *
   * <p>The returned multimap will be serializable if the specified multimap is serializable.
   *
   * @param multimap the multimap to be wrapped in a synchronized view
   * @return a synchronized view of the specified multimap
   */
  @J2ktIncompatible // Synchronized
  public static <K extends @Nullable Object, V extends @Nullable Object>

   * @return a synchronized view of the specified navigable set.
   * @since 13.0
   */
  @GwtIncompatible // NavigableSet
  @J2ktIncompatible // Synchronized
  public static <E extends @Nullable Object> NavigableSet<E> synchronizedNavigableSet(
      NavigableSet<E> navigableSet) {
    return Synchronized.navigableSet(navigableSet);
  }

                log.debug("Usage dropped to zero, release connection " + this.transport);
            }
            // Ensure atomic cleanup of all resources
            synchronized (this) {
                // Double-check usage count within synchronized block
                if (this.usageCount.get() != 0) {
                    return; // Another thread acquired the session
                }

  private class RecordingPushObserver :
    PushObserver,
    Lockable {
    val events = mutableListOf<Any>()

    @Synchronized fun takeEvent(): Any {
      while (events.isEmpty()) {
        wait()
      }
      return events.removeAt(0)
    }

    @Synchronized override fun onRequest(
      streamId: Int,
      requestHeaders: List<Header>,
    ): Boolean {

      } finally {
        add(newCloseables, directExecutor());
      }
    }

    @Override
    public void close() {
      if (closed) {
        return;
      }
      synchronized (this) {
        if (closed) {
          return;
        }
        closed = true;
      }
      for (Map.Entry<AutoCloseable, Executor> entry : entrySet()) {

    assertEquals("null=null", e.toString());
    assertEquals(0, e.hashCode());
  }

  /** See {@link SynchronizedBiMapTest} for more tests. */
  @J2ktIncompatible // Synchronized
  public void testSynchronizedBiMap() {
    BiMap<String, Integer> bimap = HashBiMap.create();
    bimap.put("one", 1);
    BiMap<String, Integer> sync = Maps.synchronizedBiMap(bimap);
    bimap.put("two", 2);

    * user agent, proxy settings, request headers, cookie store, and connection manager.
    * It also processes form-based authentication schemes and sets up the HTTP client context.
    */
    @Override
    public synchronized void init() {
        if (httpClient != null) {
            return;
        }

        if (logger.isDebugEnabled()) {
            logger.debug("Initializing {}", HcHttpClient.class.getName());
        }