}

  @Override
  @CheckForNull
  public Entry<E> pollFirstEntry() {
    return delegate().pollFirstEntry();
  }

  /**
   * A sensible definition of {@link #pollFirstEntry()} in terms of {@code entrySet().iterator()}.
   *
   * <p>If you override {@link #entrySet()}, you may wish to override {@link #pollFirstEntry()} to
   * forward to this implementation.
   */
  @CheckForNull

    }
    return result;
  }

  @Override
  @CheckForNull
  public Entry<E> pollFirstEntry() {
    return forwardMultiset().pollLastEntry();
  }

  @Override
  @CheckForNull
  public Entry<E> pollLastEntry() {
    return forwardMultiset().pollFirstEntry();
  }

  @Override
  public SortedMultiset<E> headMultiset(E toElement, BoundType boundType) {

  public void testPollFirst() {
    assertEquals(a, navigableMap.pollFirstEntry());
    assertEquals(entries.subList(1, entries.size()), copyToList(navigableMap.entrySet()));
  }

  @MapFeature.Require(absent = SUPPORTS_REMOVE)
  public void testPollFirstUnsupported() {
    assertThrows(UnsupportedOperationException.class, () -> navigableMap.pollFirstEntry());
  }

  @CollectionSize.Require(SEVERAL)

      assertTrue(Thread.holdsLock(mutex));
      return delegate().navigableKeySet();
    }

    @Override
    public @Nullable Entry<K, V> pollFirstEntry() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate().pollFirstEntry();
    }

    @Override
    public @Nullable Entry<K, V> pollLastEntry() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate().pollLastEntry();

  }

  @Override
  public NavigableSet<K> navigableKeySet() {
    return delegate.navigableKeySet();
  }

  @Override
  public @Nullable Entry<K, V> pollFirstEntry() {
    return delegate.pollFirstEntry();
  }

  @Override
  public @Nullable Entry<K, V> pollLastEntry() {
    return delegate.pollLastEntry();
  }

  @Override
  public @Nullable V put(K key, V value) {

  public void testPollFirst() {
    assertEquals(a, sortedMultiset.pollFirstEntry());
    assertEquals(asList(b, c), copyToList(sortedMultiset.entrySet()));
  }

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
  public void testPollFirstUnsupported() {
    assertThrows(UnsupportedOperationException.class, () -> sortedMultiset.pollFirstEntry());
  }

  @CollectionSize.Require(SEVERAL)
  public void testLower() {

  public void testPollFirst() {
    assertEquals(a, sortedMultiset.pollFirstEntry());
    assertEquals(asList(b, c), copyToList(sortedMultiset.entrySet()));
  }

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
  public void testPollFirstUnsupported() {
    assertThrows(UnsupportedOperationException.class, () -> sortedMultiset.pollFirstEntry());
  }

  @CollectionSize.Require(SEVERAL)
  public void testLower() {

  }

  @Override
  public NavigableSet<K> navigableKeySet() {
    return delegate.navigableKeySet();
  }

  @Override
  public @Nullable Entry<K, V> pollFirstEntry() {
    return delegate.pollFirstEntry();
  }

  @Override
  public @Nullable Entry<K, V> pollLastEntry() {
    return delegate.pollLastEntry();
  }

  @Override
  public @Nullable V put(K key, V value) {

    return delegate().firstEntry();
  }

  @Override
  @CheckForNull
  public Entry<E> lastEntry() {
    return delegate().lastEntry();
  }

  @Override
  @CheckForNull
  public Entry<E> pollFirstEntry() {
    throw new UnsupportedOperationException();
  }

  @Override
  @CheckForNull
  public Entry<E> pollLastEntry() {
    throw new UnsupportedOperationException();
  }

  @Override

    return delegate().firstEntry();
  }

  @Override
  @CheckForNull
  public Entry<E> lastEntry() {
    return delegate().lastEntry();
  }

  @Override
  @CheckForNull
  public Entry<E> pollFirstEntry() {
    throw new UnsupportedOperationException();
  }

  @Override
  @CheckForNull
  public Entry<E> pollLastEntry() {
    throw new UnsupportedOperationException();
  }

  @Override