* explained by the {@link Comparable} class specification. Otherwise, the resulting multiset will
 * violate the general contract of {@link SetMultimap}, which is specified in terms of {@link
 * Object#equals}.
 *
 * <p>The collections returned by {@code keySet} and {@code asMap} iterate through the keys

import java.util.stream.Collector;
import java.util.stream.Stream;
import org.jspecify.annotations.Nullable;

/**
 * A {@link SetMultimap} whose contents will never change, with many other important properties
 * detailed at {@link ImmutableCollection}.
 *
 * <p><b>Warning:</b> As in all {@link SetMultimap}s, do not modify either a key <i>or a value</i>
 * of a {@code ImmutableSetMultimap} in a way that affects its {@link Object#equals} behavior.

      extends SynchronizedMultimap<K, V> implements SetMultimap<K, V> {
    transient @Nullable Set<Map.Entry<K, V>> entrySet;

    SynchronizedSetMultimap(SetMultimap<K, V> delegate, @Nullable Object mutex) {
      super(delegate, mutex);
    }

    @Override
    SetMultimap<K, V> delegate() {
      return (SetMultimap<K, V>) super.delegate();
    }

    @Override

  @MapFeature.Require(SUPPORTS_REMOVE)
  /*
   * We are comparing Multimaps of the same type, so as long as they have value collections that
   * implement equals() (as with ListMultimap or SetMultimap, as opposed to a QueueMultimap or
   * something), our equality check is value-based.
   */
  @SuppressWarnings("UndefinedEquals")
  public void testRetainAllPropagatesToMultimap() {

      extends SynchronizedMultimap<K, V> implements SetMultimap<K, V> {
    transient @Nullable Set<Map.Entry<K, V>> entrySet;

    SynchronizedSetMultimap(SetMultimap<K, V> delegate, @Nullable Object mutex) {
      super(delegate, mutex);
    }

    @Override
    SetMultimap<K, V> delegate() {
      return (SetMultimap<K, V>) super.delegate();
    }

    @Override

  @J2ktIncompatible
  @AndroidIncompatible // test-suite builders
  private static final class ImmutableSetMultimapGenerator extends TestStringSetMultimapGenerator {
    @Override
    protected SetMultimap<String, String> create(Entry<String, String>[] entries) {
      ImmutableSetMultimap.Builder<String, String> builder = ImmutableSetMultimap.builder();
      for (Entry<String, String> entry : entries) {

import com.google.common.collect.Multiset;
import com.google.common.collect.Ordering;
import com.google.common.collect.Range;
import com.google.common.collect.RowSortedTable;
import com.google.common.collect.SetMultimap;
import com.google.common.collect.SortedMultiset;
import com.google.common.collect.Table;
import com.google.common.collect.TreeBasedTable;
import com.google.common.collect.TreeMultiset;

  private static final Comparator<@Nullable Integer> DECREASING_INT_COMPARATOR =
      Ordering.<Integer>natural().reverse().<Integer>nullsFirst();

  private SetMultimap<String, Integer> create() {
    return TreeMultimap.create(StringLength.COMPARATOR, DECREASING_INT_COMPARATOR);
  }

  /** Create and populate a {@code TreeMultimap} with explicit comparators. */

    }
  }

  abstract Iterator<Entry<K, V>> entryIterator();

  Spliterator<Entry<K, V>> entrySpliterator() {
    return Spliterators.spliterator(
        entryIterator(), size(), (this instanceof SetMultimap) ? Spliterator.DISTINCT : 0);
  }

  @LazyInit private transient @Nullable Set<K> keySet;

  @Override
  public Set<K> keySet() {
    Set<K> result = keySet;

import com.google.common.collect.Multiset;
import com.google.common.collect.Ordering;
import com.google.common.collect.Range;
import com.google.common.collect.RowSortedTable;
import com.google.common.collect.SetMultimap;
import com.google.common.collect.SortedMultiset;
import com.google.common.collect.Table;
import com.google.common.collect.TreeBasedTable;
import com.google.common.collect.TreeMultiset;