/**
 * This class provides a skeletal implementation of the {@link Multiset} interface. A new multiset
 * implementation can be created easily by extending this class and implementing the {@link
 * Multiset#entrySet()} method, plus optionally overriding {@link #add(Object, int)} and {@link
 * #remove(Object, int)} to enable modifications to the multiset.
 *

  public void testEquals_yes() {
    assertTrue(
        "multiset doesn't equal a multiset with the same elements",
        getMultiset().equals(HashMultiset.create(getSampleElements())));
  }

  public void testEquals_differentSize() {
    Multiset<E> other = HashMultiset.create(getSampleElements());
    other.add(e0());
    assertFalse("multiset equals a multiset with a different size", getMultiset().equals(other));
  }

  public void testEquals_yes() {
    assertTrue(
        "multiset doesn't equal a multiset with the same elements",
        getMultiset().equals(HashMultiset.create(getSampleElements())));
  }

  public void testEquals_differentSize() {
    Multiset<E> other = HashMultiset.create(getSampleElements());
    other.add(e0());
    assertFalse("multiset equals a multiset with a different size", getMultiset().equals(other));
  }

        new ImmutableMultiset.Builder<String>().addCopies("x", 10).build();
    multiset.addAll(adds);
    assertEquals(1, addCalls.get());
  }

  public void testRemoveUnsupported() {
    Multiset<String> multiset = new NoRemoveMultiset<>();
    multiset.add("a");
    assertThrows(UnsupportedOperationException.class, () -> multiset.remove("a"));
    assertTrue(multiset.contains("a"));
  }

   *
   * @param multiset the presumed-immutable multiset
   * @param sampleElement an element of the same type as that contained by {@code multiset}. {@code
   *     multiset} may or may not have {@code sampleElement} as a member.
   */
  public static <E extends @Nullable Object> void assertMultisetIsUnmodifiable(
      Multiset<E> multiset, E sampleElement) {
    Multiset<E> copy = LinkedHashMultiset.create(multiset);

    multiset.add("foo", 2);
    multiset.add("bar");
    assertEquals(3, multiset.size());
    assertEquals(2, multiset.count("foo"));
    assertEquals("[foo x 2, bar]", multiset.toString());
  }

  public void testCreateFromIterable() {
    Multiset<String> multiset = TreeMultiset.create(asList("foo", "bar", "foo"));
    assertEquals(3, multiset.size());
    assertEquals(2, multiset.count("foo"));

import com.google.common.collect.testing.features.CollectionSize;
import java.lang.reflect.Method;
import java.util.List;
import org.junit.Ignore;

/**
 * Tests for {@code Multiset#remove}, {@code Multiset.removeAll}, and {@code Multiset.retainAll} not
 * already covered by the corresponding Collection testers.
 *
 * @author Jared Levy
 */
@GwtCompatible

import com.google.common.collect.testing.features.CollectionSize;
import java.lang.reflect.Method;
import java.util.List;
import org.junit.Ignore;

/**
 * Tests for {@code Multiset#remove}, {@code Multiset.removeAll}, and {@code Multiset.retainAll} not
 * already covered by the corresponding Collection testers.
 *
 * @author Jared Levy
 */
@GwtCompatible

@GwtCompatible
public enum MultisetFeature implements Feature<Multiset> {
  /**
   * Indicates that elements from {@code Multiset.entrySet()} update to reflect changes in the
   * backing multiset.
   */
  ENTRIES_ARE_VIEWS;

  @Override
  public Set<Feature<? super Multiset>> getImpliedFeatures() {
    return emptySet();
  }

  @Retention(RetentionPolicy.RUNTIME)
  @Inherited

  /*
   * As the class docs say, this test only makes sense for collections that define equals().
   * Accordingly, our testing framework adds it only when testing an implementation of List, Set, or
   * Multiset.
   */
  @SuppressWarnings("UndefinedEquals")
  public void testReserialize() {
    assertEquals(SerializableTester.reserialize(actualContents()), actualContents());
  }