}

        @Override
        public boolean removeAll(Collection<?> c) {
          return delegate.keySet().removeAll(c);
        }

        @Override
        public boolean retainAll(Collection<?> c) {
          return delegate.keySet().retainAll(c);
        }
      };
    }

    @Override
    public Collection<V> values() {
      return new ForwardingCollection<V>() {
        @Override

    }

    @Override
    public boolean containsAll(Collection<?> collection) {
      return standardContainsAll(collection);
    }

    @Override
    public boolean remove(Object object) {
      return standardRemove(object);
    }

    @Override
    public boolean removeAll(Collection<?> collection) {
      return standardRemoveAll(collection);
    }

    @Override

      return standardRemove(object);
    }

    @Override
    public boolean removeAll(Collection<?> collection) {
      return standardRemoveAll(collection);
    }

    @Override
    public boolean retainAll(Collection<?> collection) {
      return standardRetainAll(collection);
    }

    @Override
    public int size() {
      return standardSize();
    }

    @Override

      return standardRemove(object);
    }

    @Override
    public boolean removeAll(Collection<?> collection) {
      return standardRemoveAll(collection);
    }

    @Override
    public boolean retainAll(Collection<?> collection) {
      return standardRetainAll(collection);
    }

    @Override
    public Object[] toArray() {
      return standardToArray();
    }

      return standardRemove(object);
    }

    @Override
    public boolean removeAll(Collection<?> collection) {
      return standardRemoveAll(collection);
    }

    @Override
    public boolean retainAll(Collection<?> collection) {
      return standardRetainAll(collection);
    }

    @Override
    public Object[] toArray() {
      return standardToArray();
    }

    assertTrue("An Object should be equal to itself.", collection.equals(collection));
  }

  // Comparisons to null *are* defined.
  @SuppressWarnings("UndefinedEquals")
  public void testEquals_null() {
    // noinspection ObjectEqualsNull
    assertFalse("An object should not be equal to null.", collection.equals(null));
  }

  // A collection should essentially never be equal to a non-collection.
  @SuppressWarnings("UndefinedEquals")

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testClear() {
    collection.clear();
    assertTrue("After clear(), a collection should be empty.", collection.isEmpty());
    assertEquals(0, collection.size());
    assertFalse(collection.iterator().hasNext());
  }

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)

  public void testCopyOf_shortcut_empty() {
    Collection<String> c = ImmutableMultiset.of();
    assertSame(c, ImmutableMultiset.copyOf(c));
  }

  public void testCopyOf_shortcut_singleton() {
    Collection<String> c = ImmutableMultiset.of("a");
    assertSame(c, ImmutableMultiset.copyOf(c));
  }

  public void testCopyOf_shortcut_immutableMultiset() {
    Collection<String> c = ImmutableMultiset.of("a", "b", "c");

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.BiMap;
import com.google.common.collect.testing.AbstractMapTester;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map.Entry;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;
import org.junit.Ignore;

/** Skeleton for a tester of a {@code BiMap}. */

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.testing.features.CollectionSize;
import java.util.Collection;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * The subject-generator interface accepted by Collection testers, for testing a Collection at one
 * particular {@link CollectionSize}.
 *
 * <p>This interface should not be implemented outside this package; {@link