return delegate.poll();
    }

    @Override
    public E remove() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.remove();
    }

    @Override
    public boolean remove(Object object) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.remove(object);
    }

    @Override
    public @Nullable E peek() {

      return Iterators.filter(unfiltered.iterator(), predicate);
    }

    @Override
    public boolean remove(@CheckForNull Object element) {
      return contains(element) && unfiltered.remove(element);
    }

    @Override
    public boolean removeAll(final Collection<?> collection) {
      boolean changed = false;
      Iterator<E> itr = unfiltered.iterator();
      while (itr.hasNext()) {

# Release 2.12.0

### Breaking Changes

*   Build, Compilation and Packaging

    return asMap().get(key) != null;
  }

  @Override
  public Collection<V> removeAll(@CheckForNull Object key) {
    return MoreObjects.firstNonNull(asMap().remove(key), unmodifiableEmptyCollection());
  }

  Collection<V> unmodifiableEmptyCollection() {
    // These return false, rather than throwing a UOE, on remove calls.
    return (unfiltered instanceof SetMultimap)
        ? Collections.<V>emptySet()

      return delegate.poll();
    }

    @Override
    public E remove() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.remove();
    }

    @Override
    public boolean remove(Object object) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.remove(object);
    }

    @Override
    public @Nullable E peek() {

        iterator.hasNext());
    iterator.remove();
    assertTrue(
        "multiset isn't empty after multiset.entrySet() iterator.remove()",
        getMultiset().isEmpty());
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testEntrySet_removePresent() {
    assertTrue(
        "multiset.entrySet.remove(presentEntry) returned false",

  /**
   * Removes the mapping, if any, associated with the given keys.
   *
   * @param rowKey row key of mapping to be removed
   * @param columnKey column key of mapping to be removed
   * @return the value previously associated with the keys, or {@code null} if no such value existed
   */
  @CanIgnoreReturnValue
  @CheckForNull
  V remove(
      @CompatibleWith("R") @CheckForNull Object rowKey,

      return delegate.poll();
    }

    @Override
    public E remove() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.remove();
    }

    @Override
    public boolean remove(Object object) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.remove(object);
    }

    @Override
    public @Nullable E peek() {

    // Test #remove()
    try {
      multimap.remove(sampleKey, sampleValue);
      fail("remove succeeded on unmodifiable multimap");
    } catch (UnsupportedOperationException expected) {
    }
    assertMultimapRemainsUnmodified(multimap, originalEntries);

    // Test #removeAll()
    try {
      multimap.removeAll(sampleKey);
      fail("removeAll succeeded on unmodifiable multimap");

        iterator.hasNext());
    iterator.remove();
    assertTrue(
        "multiset isn't empty after multiset.entrySet() iterator.remove()",
        getMultiset().isEmpty());
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testEntrySet_removePresent() {
    assertTrue(
        "multiset.entrySet.remove(presentEntry) returned false",