public Collection<V> removeAll(@Nullable Object key) {
    return MoreObjects.firstNonNull(asMap().remove(key), unmodifiableEmptyCollection());
  }

  @SuppressWarnings("EmptyList") // ImmutableList doesn't support nullable element types
  Collection<V> unmodifiableEmptyCollection() {
    // These return false, rather than throwing a UOE, on remove calls.
    return (unfiltered instanceof SetMultimap) ? emptySet() : emptyList();
  }

    /* Should complain on attempt to remove() after peek(). */
    assertThrows(IllegalStateException.class, () -> peekingIterator.remove());

    assertEquals(
        "After remove() throws exception, peek should still be ok", "B", peekingIterator.peek());

    /* Should recover to be able to remove() after next(). */
    assertEquals("B", peekingIterator.next());
    peekingIterator.remove();

        return delegate().iterator();
      }

      @Override
      public int size() {
        return delegate().size();
      }

      @Override
      public boolean remove(Object o) {
        return delegate().remove(o);
      }

      @Override
      public void clear() {
        delegate().clear();
      }
    };
  }

  @Override
  public @Nullable Entry<K, V> firstEntry() {

public class SetRemoveTester<E> extends AbstractSetTester<E> {
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testRemove_present() {
    getSet().remove(e0());
    assertFalse(
        "After remove(present) a set should not contain the removed element.",
        getSet().contains(e0()));
  }

public class SetRemoveTester<E> extends AbstractSetTester<E> {
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testRemove_present() {
    getSet().remove(e0());
    assertFalse(
        "After remove(present) a set should not contain the removed element.",
        getSet().contains(e0()));
  }

import java.util.function.Consumer;
import org.jspecify.annotations.Nullable;

/**
 * CompactHashMap is an implementation of a Map. All optional operations (put and remove) are
 * supported. Null keys and values are supported.
 *
 * <p>{@code containsKey(k)}, {@code put(k, v)} and {@code remove(k)} are all (expected and
 * amortized) constant time operations. Expected in the hashtable sense (depends on the hash

    assertTrue(map.containsKey(one));
    assertTrue(map.containsValue(one));
    assertSame(one, map.remove(one));
    assertEquals(0, map.size());

    cache.getUnchecked(one);
    assertEquals(1, map.size());
    assertFalse(map.remove(one, two));
    assertTrue(map.remove(one, one));
    assertEquals(0, map.size());

    cache.getUnchecked(one);

                    // Stop async notification monitoring
                    stopAsyncNotificationMonitoring(registration.getRegistrationId());

                    registrations.remove(registration.getRegistrationId());
                    listeners.remove(registration.getRegistrationId());

                    log.info("Successfully unregistered witness: {}", registration.getRegistrationId());
                } else {

          }

          @Override
          public T next() {
            return listIter.previous();
          }

          @Override
          public void remove() {
            listIter.remove();
          }
        };
  }

  static <T extends @Nullable Object> Iterator<T> cycle(Iterable<T> iterable) {
    return new Iterator<T>() {

        // If createTransport returns null (no mock setup), remove immediately
        try {
            SmbTransport testTransport = manager.createTransport(failedChannel.getLocalInterface(), failedChannel.getRemoteInterface());
            if (testTransport == null) {
                // No recovery possible, remove synchronously
                removeChannel(failedChannel);
                return;
            }