import com.google.common.collect.Multimap;

/**
 * Helper methods/assertions for use with {@code com.google.common.collect} types.
 *
 * @author Colin Decker
 */
@GwtCompatible
final class GoogleHelpers {

  private GoogleHelpers() {}

  static void assertEmpty(Multimap<?, ?> multimap) {
    if (!multimap.isEmpty()) {
      fail("Not true that " + multimap + " is empty");
    }
  }

  public enum ListMultimapImpl {
    ArrayListMultimapImpl {
      @Override
      <K, V> ListMultimap<K, V> create(Multimap<K, V> contents) {
        return ArrayListMultimap.create(contents);
      }
    },
    LinkedListMultimapImpl {
      @Override
      <K, V> ListMultimap<K, V> create(Multimap<K, V> contents) {
        return LinkedListMultimap.create(contents);
      }
    },
    ImmutableListMultimapImpl {

  public void testTreeKeys() {
    ListMultimap<String, Integer> multimap = MultimapBuilder.treeKeys().arrayListValues().build();
    assertTrue(multimap.keySet() instanceof SortedSet);
    assertTrue(multimap.asMap() instanceof SortedMap);
  }

  public void testTreeKeys_gwtCompatible() {
    ListMultimap<String, Integer> multimap =

  @CollectionSize.Require(SEVERAL)
  public void testMultimapRemoveDeletesFirstOccurrence() {
    resetContainer(mapEntry(k0(), v0()), mapEntry(k0(), v1()), mapEntry(k0(), v0()));

    List<V> list = multimap().get(k0());
    multimap().remove(k0(), v0());
    assertContentsInOrder(list, v1(), v0());
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(SEVERAL)
  public void testRemoveAtIndexFromGetPropagates() {

  public void testPutDuplicateValue() {
    List<Entry<K, V>> entries = copyToList(multimap().entries());

    for (Entry<K, V> entry : entries) {
      resetContainer();

      K k = entry.getKey();
      V v = entry.getValue();

      List<V> values = multimap().get(k);
      List<V> expectedValues = copyToList(values);

      assertTrue(multimap().put(k, v));
      expectedValues.add(v);
      assertGet(k, expectedValues);

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.List;
import org.jspecify.annotations.Nullable;

/**
 * A list multimap which forwards all its method calls to another list multimap. Subclasses should
 * override one or more methods to modify the behavior of the backing multimap as desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *

import java.util.Map.Entry;
import org.jspecify.annotations.Nullable;

/**
 * An interface for all filtered multimap types.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
interface FilteredMultimap<K extends @Nullable Object, V extends @Nullable Object>
    extends Multimap<K, V> {
  Multimap<K, V> unfiltered();

  Predicate<? super Entry<K, V>> entryPredicate();

  public enum ListMultimapImpl {
    ArrayListMultimapImpl {
      @Override
      <K, V> ListMultimap<K, V> create(Multimap<K, V> contents) {
        return ArrayListMultimap.create(contents);
      }
    },
    LinkedListMultimapImpl {
      @Override
      <K, V> ListMultimap<K, V> create(Multimap<K, V> contents) {
        return LinkedListMultimap.create(contents);
      }
    },
    ImmutableListMultimapImpl {

import java.util.Map.Entry;
import org.jspecify.annotations.Nullable;

/**
 * An interface for all filtered multimap types.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
interface FilteredMultimap<K extends @Nullable Object, V extends @Nullable Object>
    extends Multimap<K, V> {
  Multimap<K, V> unfiltered();

  Predicate<? super Entry<K, V>> entryPredicate();

  }

  static <K extends @Nullable Object, V extends @Nullable Object> Multimap<K, V> multimap(
      Multimap<K, V> multimap, @Nullable Object mutex) {
    if (multimap instanceof SynchronizedMultimap || multimap instanceof BaseImmutableMultimap) {
      return multimap;
    }
    return new SynchronizedMultimap<>(multimap, mutex);
  }