boolean didRemove = entrySet.retainAll(entriesToRetain);
      assertEquals(shouldRemove, didRemove);
      assertEquals(entriesToRetain.size(), map.size());
      for (Entry<K, V> entry : entriesToRetain) {
        assertTrue(entrySet.contains(entry));
      }
    } else {
      assertThrows(UnsupportedOperationException.class, () -> entrySet.retainAll(entriesToRetain));
    }
    assertInvariants(map);

      assertTrue(Thread.holdsLock(mutex));
      return delegate.addAll(collection);
    }

    @Override
    public boolean retainAll(Collection<?> collection) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.retainAll(collection);
    }

    @Override
    public void clear() {
      assertTrue(Thread.holdsLock(mutex));
      delegate.clear();
    }

  }

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

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

  @Override
  public int size() {
    return delegate.size();
  }

  @Override
  public NavigableSet<E> subSet(

      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();
    }

    @Override

    }

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

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

    @Override
    public Map<String, Object> set(final int index, final Map<String, Object> element) {
        return parent.set(index, element);
    }

    return Multisets.removeAllImpl(this, elementsToRemove);
  }

  /**
   * A sensible definition of {@link #retainAll} in terms of the {@code retainAll} method of {@link
   * #elementSet}. If you override {@link #elementSet}, you may wish to override {@link #retainAll}
   * to forward to this implementation.
   *
   * @since 7.0
   */
  @Override

                  return map.entrySet().removeAll(c);
                }

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

                @Override
                public int hashCode() {
                  return map.entrySet().hashCode();
                }

    return Multisets.removeAllImpl(this, elementsToRemove);
  }

  /**
   * A sensible definition of {@link #retainAll} in terms of the {@code retainAll} method of {@link
   * #elementSet}. If you override {@link #elementSet}, you may wish to override {@link #retainAll}
   * to forward to this implementation.
   *
   * @since 7.0
   */
  @Override

    Multimap<String, Integer> filtered = filterValues(keyFiltered, VALUE_PREDICATE);
    assertEquals(1, filtered.size());
    assertTrue(filtered.containsEntry("foo", 1));
    assertTrue(filtered.keySet().retainAll(asList("cat", "dog")));
    assertEquals(0, filtered.size());
  }

  // TODO(jlevy): Many more tests needed.

            throw uoe();
        }

        @Override
        public boolean remove(Object o) {
            throw uoe();
        }

        @Override
        public boolean retainAll(Collection<?> c) {
            throw uoe();
        }

        @Override
        public void clear() {
            throw uoe();
        }

        @Override