assertSame("bar", sortedTable.rowKeySet().first());
  }

  public void testRowKeySetLast() {
    sortedTable = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    assertSame("foo", sortedTable.rowKeySet().last());
  }

  public void testRowKeySetHeadSet() {
    sortedTable = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    Set<String> set = sortedTable.rowKeySet().headSet("cat");

  private static <R, C, V> void validateViewOrdering(Table<R, C, V> original, Table<R, C, V> copy) {
    assertThat(copy.cellSet()).containsExactlyElementsIn(original.cellSet()).inOrder();
    assertThat(copy.rowKeySet()).containsExactlyElementsIn(original.rowKeySet()).inOrder();
    assertThat(copy.values()).containsExactlyElementsIn(original.values()).inOrder();
  }

  public void testCopyOf() {

                    populateForRowKeySet(table, elements);
                    return table.rowKeySet();
                  }
                })
            .named("ArrayTable.rowKeySet")
            .withFeatures(
                CollectionSize.ONE,
                CollectionSize.SEVERAL,
                CollectionFeature.KNOWN_ORDER,

                    populateForRowKeySet(table, elements);
                    return table.rowKeySet();
                  }
                })
            .named("ArrayTable.rowKeySet")
            .withFeatures(
                CollectionSize.ONE,
                CollectionSize.SEVERAL,
                CollectionFeature.KNOWN_ORDER,

      checkArgument(rangeContains(checkNotNull(key)));
      return super.put(key, value);
    }
  }

  // rowKeySet() and rowMap() are defined here so they appear in the Javadoc.

  @Override
  public SortedSet<R> rowKeySet() {
    return super.rowKeySet();
  }

  @Override
  public SortedMap<R, Map<C, V>> rowMap() {
    return super.rowMap();
  }

    Table<String, Integer, Character> transpose = transpose(original);
    original.put(1, "foo", 'a');
    assertSame(original.columnKeySet(), transpose.rowKeySet());
    assertSame(original.rowKeySet(), transpose.columnKeySet());
    assertSame(original.columnMap(), transpose.rowMap());
    assertSame(original.rowMap(), transpose.columnMap());
    assertSame(original.values(), transpose.values());

   *
   * <p>The returned table allows subsequent {@code put} calls with the row keys in {@code
   * table.rowKeySet()} and the column keys in {@code table.columnKeySet()}. Calling {@link #put}
   * with other keys leads to an {@code IllegalArgumentException}.
   *
   * <p>The ordering of {@code table.rowKeySet()} and {@code table.columnKeySet()} determines the
   * row and column iteration ordering of the returned table.
   *

    populate(table, data);
    return table;
  }

  public void testRowKeySetOrdering() {
    table = create("foo", 3, 'a', "bar", 1, 'b', "foo", 2, 'c');
    assertThat(table.rowKeySet()).containsExactly("foo", "bar").inOrder();
  }

  public void testRowOrdering() {
    table = create("foo", 3, 'a', "bar", 1, 'b', "foo", 2, 'c');
    assertThat(table.row("foo").keySet()).containsExactly(2, 3).inOrder();

    checkNotNull(rowKey, "rowKey");
    return MoreObjects.firstNonNull(
        (ImmutableMap<C, V>) rowMap().get(rowKey), ImmutableMap.<C, V>of());
  }

  @Override
  public ImmutableSet<R> rowKeySet() {
    return rowMap().keySet();
  }

  /**
   * {@inheritDoc}
   *
   * <p>The value {@code Map<C, V>} instances in the returned map are {@link ImmutableMap} instances
   * as well.
   */

      synchronized (mutex) {
        return set(delegate().cellSet(), mutex);
      }
    }

    @Override
    public Set<R> rowKeySet() {
      synchronized (mutex) {
        return set(delegate().rowKeySet(), mutex);
      }
    }

    @Override
    public Set<C> columnKeySet() {
      synchronized (mutex) {
        return set(delegate().columnKeySet(), mutex);