}
        }
        return endOfData();
      }
    }

    @Override
    Set<R> createKeySet() {
      return new KeySet();
    }

    @WeakOuter
    private final class KeySet extends Maps.KeySet<R, V> {
      KeySet() {
        super(Column.this);
      }

      @Override
      public boolean contains(@Nullable Object obj) {

  @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()));
  }

  @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()));
  }

    }
  }

  private transient @Nullable ImmutableSortedSet<K> keySet;

  @Override
  public ImmutableSortedSet<K> keySet() {
    ImmutableSortedSet<K> ks = keySet;
    return (ks == null) ? (keySet = createKeySet()) : ks;
  }

  @Override
  ImmutableSortedSet<K> createKeySet() {
    // the keySet() of the delegate is only a Set and TreeMap.navigatableKeySet

    builder.orderKeysBy(Collections.reverseOrder());
    builder.put("c", 4);
    builder.put("a", 2);
    builder.put("b", 6);
    ImmutableSetMultimap<String, Integer> multimap = builder.build();
    assertThat(multimap.keySet()).containsExactly("d", "c", "b", "a").inOrder();
    assertThat(multimap.values()).containsExactly(2, 4, 3, 6, 5, 2).inOrder();
    assertThat(multimap.get("a")).containsExactly(5, 2).inOrder();

        Set<?> set = (Set<?>) obj;
        return inputSet.keySet().containsAll(set);
      }
      return false;
    }

    @Override
    public boolean equals(@Nullable Object obj) {
      if (obj instanceof PowerSet) {
        PowerSet<?> that = (PowerSet<?>) obj;
        return inputSet.keySet().equals(that.inputSet.keySet());
      }
      return super.equals(obj);
    }

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import java.io.Serializable;
import org.jspecify.annotations.Nullable;

/**
 * {@code keySet()} implementation for {@link ImmutableMap}.
 *
 * @author Jesse Wilson
 * @author Kevin Bourrillion
 */
@GwtCompatible
final class ImmutableMapKeySet<K, V> extends IndexedImmutableSet<K> {

      null
    }

  override fun trustManager(sslSocketFactory: SSLSocketFactory): X509TrustManager? {
    // Not supported due to access checks on JDK 9+:
    // java.lang.reflect.InaccessibleObjectException: Unable to make member of class
    // sun.security.ssl.SSLSocketFactoryImpl accessible:  module java.base does not export
    // sun.security.ssl to unnamed module @xxx
    throw UnsupportedOperationException(

  protected final void assertInvariants(Map<K, V> map) {
    Set<K> keySet = map.keySet();
    Collection<V> valueCollection = map.values();
    Set<Entry<K, V>> entrySet = map.entrySet();

    assertEquals(map.size() == 0, map.isEmpty());
    assertEquals(map.size(), keySet.size());
    assertEquals(keySet.size() == 0, keySet.isEmpty());
    assertEquals(!keySet.isEmpty(), keySet.iterator().hasNext());

    int expectedKeySetHash = 0;

    assertTrue(getMap().isEmpty());
    assertTrue(inv.isEmpty());
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testKeySetClearClearsInverse() {
    BiMap<V, K> inv = getMap().inverse();
    getMap().keySet().clear();
    assertTrue(getMap().isEmpty());
    assertTrue(inv.isEmpty());
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testValuesClearClearsInverse() {
    BiMap<V, K> inv = getMap().inverse();