}
  }

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

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

    }
  }

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

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

      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();

   * @deprecated Unsupported operation.
   */
  @CanIgnoreReturnValue
  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  public final @Nullable Entry<E> pollFirstEntry() {
    throw new UnsupportedOperationException();
  }

  /**
   * {@inheritDoc}
   *
   * <p>This implementation is guaranteed to throw an {@link UnsupportedOperationException}.
   *

  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() {

   * @deprecated Unsupported operation.
   */
  @CanIgnoreReturnValue
  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  public final @Nullable Entry<E> pollFirstEntry() {
    throw new UnsupportedOperationException();
  }

  /**
   * {@inheritDoc}
   *
   * <p>This implementation is guaranteed to throw an {@link UnsupportedOperationException}.
   *

      Entry<K, Collection<V>> entry = sortedMap().lastEntry();
      return (entry == null) ? null : wrapEntry(entry);
    }

    @Override
    public @Nullable Entry<K, Collection<V>> pollFirstEntry() {
      return pollAsMapEntry(entrySet().iterator());
    }

    @Override
    public @Nullable Entry<K, Collection<V>> pollLastEntry() {

      Entry<K, Collection<V>> entry = sortedMap().lastEntry();
      return (entry == null) ? null : wrapEntry(entry);
    }

    @Override
    public @Nullable Entry<K, Collection<V>> pollFirstEntry() {
      return pollAsMapEntry(entrySet().iterator());
    }

    @Override
    public @Nullable Entry<K, Collection<V>> pollLastEntry() {