assertThat(multimap.keySet()).containsExactly("foo", "bar", "cow").inOrder();
    assertThat(multimap.removeAll("foo")).containsExactly(6, 7).inOrder();
    assertThat(multimap.keySet()).containsExactly("bar", "cow").inOrder();
    assertTrue(multimap.remove("bar", 4));
    assertThat(multimap.keySet()).containsExactly("bar", "cow").inOrder();
    assertTrue(multimap.remove("bar", 1));

    return new RowSortedMap();
  }

  @WeakOuter
  private final class RowSortedMap extends RowMap implements SortedMap<R, Map<C, V>> {
    @Override
    public SortedSet<R> keySet() {
      return (SortedSet<R>) super.keySet();
    }

    @Override
    SortedSet<R> createKeySet() {
      return new Maps.SortedKeySet<>(this);
    }

    @Override

                        ArrayTable.create(rowKeys, columnKeys);
                    populateForRowKeySet(table, elements);
                    return table.column(1).keySet();
                  }
                })
            .named("ArrayTable.column.keySet")
            .withFeatures(
                CollectionSize.ONE,
                CollectionSize.SEVERAL,
                CollectionFeature.KNOWN_ORDER,

  }

  @Override
  SortedMap<K, Collection<V>> backingMap() {
    return (SortedMap<K, Collection<V>>) super.backingMap();
  }

  @Override
  public SortedSet<K> keySet() {
    return (SortedSet<K>) super.keySet();
  }

  @Override
  Set<K> createKeySet() {
    return createMaybeNavigableKeySet();
  }

      Set<Object> keys = cache.asMap().keySet();
      assertThrows(NullPointerException.class, () -> keys.toArray((Object[]) null));
      checkEmpty(cache);
    }
  }

  public void testKeySet_addNotSupported() {
    for (LoadingCache<Object, Object> cache : caches()) {
      assertThrows(UnsupportedOperationException.class, () -> cache.asMap().keySet().add(1));

      assertThrows(

      Set<Object> keys = cache.asMap().keySet();
      assertThrows(NullPointerException.class, () -> keys.toArray((Object[]) null));
      checkEmpty(cache);
    }
  }

  public void testKeySet_addNotSupported() {
    for (LoadingCache<Object, Object> cache : caches()) {
      assertThrows(UnsupportedOperationException.class, () -> cache.asMap().keySet().add(1));

      assertThrows(

      return delegate;
    }

    @Override
    public Set<K> keySet() {
      return new ForwardingSet<K>() {
        @Override
        protected Set<K> delegate() {
          return delegate.keySet();
        }

        @Override
        public Iterator<K> iterator() {
          return Iterators.unmodifiableIterator(delegate.keySet().iterator());
        }

        @Override

    return new RowSortedMap();
  }

  @WeakOuter
  private final class RowSortedMap extends RowMap implements SortedMap<R, Map<C, V>> {
    @Override
    public SortedSet<R> keySet() {
      return (SortedSet<R>) super.keySet();
    }

    @Override
    SortedSet<R> createKeySet() {
      return new Maps.SortedKeySet<>(this);
    }

    @Override

    }

    @Override
    public void remove() {
      iterator.remove();
    }
  }

  Set<K> keySet;

  @Override
  public Set<K> keySet() {
    // does not impact recency ordering
    Set<K> ks = keySet;
    return (ks != null) ? ks : (keySet = new KeySet(this));
  }

  Collection<V> values;

  @Override
  public Collection<V> values() {

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testRemove_present() {
    getSet().remove(e0());
    assertFalse(
        "After remove(present) a set should not contain the removed element.",
        getSet().contains(e0()));
  }