*
   * @throws NullPointerException if any key or value in {@code multimap} is null
   */
  public static <K, V> ImmutableSetMultimap<K, V> copyOf(
      Multimap<? extends K, ? extends V> multimap) {
    return copyOf(multimap, null);
  }

  private static <K, V> ImmutableSetMultimap<K, V> copyOf(
      Multimap<? extends K, ? extends V> multimap,
      @Nullable Comparator<? super V> valueComparator) {

import com.google.common.collect.Multimap;
import com.google.common.collect.testing.SampleElements;
import com.google.common.collect.testing.TestContainerGenerator;
import java.util.Collection;
import java.util.Map.Entry;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Creates multimaps, containing sample elements, to be tested.
 *
 * @author Louis Wasserman

import com.google.common.collect.Multimap;
import com.google.common.collect.testing.SampleElements;
import com.google.common.collect.testing.TestContainerGenerator;
import java.util.Collection;
import java.util.Map.Entry;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Creates multimaps, containing sample elements, to be tested.
 *
 * @author Louis Wasserman

import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link Multimaps#filterEntries(Multimap, Predicate)}.
 *
 * @author Jared Levy
 * @author Louis Wasserman
 */
@GwtCompatible
class FilteredEntryMultimap<K extends @Nullable Object, V extends @Nullable Object>
    extends AbstractMultimap<K, V> implements FilteredMultimap<K, V> {
  final Multimap<K, V> unfiltered;
  final Predicate<? super Entry<K, V>> predicate;

   * Multimap}. The new multimap has the same {@link Multimap#entries()} iteration order as the
   * input multimap.
   *
   * @param multimap the multimap whose contents are copied to this multimap
   */
  public static <K extends @Nullable Object, V extends @Nullable Object>
      LinkedListMultimap<K, V> create(Multimap<? extends K, ? extends V> multimap) {
    return new LinkedListMultimap<>(multimap);

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Predicate;
import java.util.List;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link Multimaps#filterKeys(ListMultimap, Predicate)}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
final class FilteredKeyListMultimap<K extends @Nullable Object, V extends @Nullable Object>

    assertEquals(0, multimap().size());
    assertEmpty(multimap());
    assertEquals(multimap(), getSubjectGenerator().create());
    assertEmpty(multimap().entries());
    assertEmpty(multimap().asMap());
    assertEmpty(multimap().keySet());
    assertEmpty(multimap().keys());
    assertEmpty(multimap().values());
    for (K key : sampleKeys()) {
      assertGet(key);
    }
  }

  @MapFeature.Require(SUPPORTS_REMOVE)

  public void testPutAllIntoEmpty() {
    Multimap<K, V> target = getSubjectGenerator().create();
    assertEquals(!multimap().isEmpty(), target.putAll(multimap()));
    assertEquals(multimap(), target);
  }

  @MapFeature.Require(SUPPORTS_PUT)
  public void testPutAll() {
    Multimap<K, V> source =
        getSubjectGenerator().create(mapEntry(k0(), v3()), mapEntry(k3(), v3()));
    assertTrue(multimap().putAll(source));

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Predicate;
import java.util.Map.Entry;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link Multimaps#filterKeys(SetMultimap, Predicate)}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
final class FilteredKeySetMultimap<K extends @Nullable Object, V extends @Nullable Object>

    assertEquals(0, multimap().size());
    assertEmpty(multimap());
    assertEquals(multimap(), getSubjectGenerator().create());
    assertEmpty(multimap().entries());
    assertEmpty(multimap().asMap());
    assertEmpty(multimap().keySet());
    assertEmpty(multimap().keys());
    assertEmpty(multimap().values());
    for (K key : sampleKeys()) {
      assertGet(key);
    }
  }

  @MapFeature.Require(SUPPORTS_REMOVE)