toRemove = mapEntry;
        return mapEntry.getKey();
      }

      @Override
      public void remove() {
        checkState(toRemove != null, "no calls to next() since the last call to remove()");
        size -= toRemove.getValue().getAndSet(0);
        backingEntries.remove();
        toRemove = null;
      }
    };
  }

  @Override

package once

// Singleton contains a pointer to T that must be set once.
// Until the value is set all Get() calls will block.
type Singleton[T any] struct {
	v   *T
	set chan struct{}
}

// NewSingleton creates a new unset singleton.
func NewSingleton[T any]() *Singleton[T] {
	return &Singleton[T]{set: make(chan struct{}), v: nil}
}

// Get will return the singleton value.
func (s *Singleton[T]) Get() *T {
	<-s.set
	return s.v

    // TODO: test whether null is supported (create a Feature)
    /**
     * The elements to be returned by future calls to {@code next()}, with the first at the top of
     * the stack.
     */
    final Stack<E> nextElements = new Stack<>();

    /**
     * The elements to be returned by future calls to {@code previous()}, with the first at the top
     * of the stack.
     */

    val client =
      OkHttpClient
        .Builder()
        .connectionPool(poolApi)
        .build()
    val call = client.newCall(Request(addressA.url)) as RealCall
    call.enterNetworkInterceptorExchange(call.request(), true, factory.newChain(call))
    c1.withLock { call.acquireConnectionNoEvents(c1) }

    // Running at time 50, the pool returns that nothing can be evicted until time 150.

  }

  /**
   * Constructs an iterator across a sequence of the given size with the given initial position.
   * That is, the first call to {@link #nextIndex()} will return {@code position}, and the first
   * call to {@link #next()} will return the element at that index, if available. Calls to {@link
   * #previous()} can retrieve the preceding {@code position} elements.
   *

    val request = Request(server.url("/a"))
    val call = client.newCall(request)
    call.enqueue(
      object : Callback {
        override fun onFailure(
          call: Call,
          e: IOException,
        ) {
          failureRef.set(true)
          latch.countDown()
        }

        override fun onResponse(
          call: Call,
          response: Response,
        ) {

        }, "remove() should not throw any exception");
    }

    @Test
    @DisplayName("EmptyIterator should behave consistently across multiple calls")
    void testConsistentBehavior() {
        // When & Then - test multiple sequential calls
        for (int i = 0; i < 10; i++) {
            assertFalse(emptyIterator.hasNext(), "hasNext should consistently return false");

    if (call.connection != null) {
      check(toClose == null)
      return ReusePlan(candidate)
    }

    // The call's connection was released.
    toClose?.closeQuietly()
    call.eventListener.connectionReleased(call, candidate)
    candidate.connectionListener.connectionReleased(candidate, call)
    if (toClose != null) {
      candidate.connectionListener.connectionClosed(candidate)

    // TODO: test whether null is supported (create a Feature)
    /**
     * The elements to be returned by future calls to {@code next()}, with the first at the top of
     * the stack.
     */
    final Stack<E> nextElements = new Stack<>();

    /**
     * The elements to be returned by future calls to {@code previous()}, with the first at the top
     * of the stack.
     */

     */
    List<FileNotifyInformation> watch() throws CIFSException;

    /**
     * {@inheritDoc}
     *
     * @see java.util.concurrent.Callable#call()
     */
    @Override
    List<FileNotifyInformation> call() throws CIFSException;

    /**
     * {@inheritDoc}
     *
     * @see java.lang.AutoCloseable#close()
     */
    @Override
    void close() throws CIFSException;