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

            'X');
    assertEquals("[20, 15, 10, 5, 3, 2, 1]", table.columnKeySet().toString());
  }

  public void testColumnKeySet_empty() {
    table = create();
    assertEquals("[]", table.columnKeySet().toString());
  }

  public void testColumnKeySet_oneRow() {
    table = create("a", 2, 'X', "a", 1, 'X');
    assertEquals("[1, 2]", table.columnKeySet().toString());
  }

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

            'X');
    assertEquals("[20, 15, 10, 5, 3, 2, 1]", table.columnKeySet().toString());
  }

  public void testColumnKeySet_empty() {
    table = create();
    assertEquals("[]", table.columnKeySet().toString());
  }

  public void testColumnKeySet_oneRow() {
    table = create("a", 2, 'X', "a", 1, 'X');
    assertEquals("[1, 2]", table.columnKeySet().toString());
  }

    delegate().clear();
  }

  @Override
  public Map<R, V> column(@ParametricNullness C columnKey) {
    return delegate().column(columnKey);
  }

  @Override
  public Set<C> columnKeySet() {
    return delegate().columnKeySet();
  }

  @Override
  public Map<C, Map<R, V>> columnMap() {
    return delegate().columnMap();
  }

  @Override

    delegate().clear();
  }

  @Override
  public Map<R, V> column(@ParametricNullness C columnKey) {
    return delegate().column(columnKey);
  }

  @Override
  public Set<C> columnKeySet() {
    return delegate().columnKeySet();
  }

  @Override
  public Map<C, Map<R, V>> columnMap() {
    return delegate().columnMap();
  }

  @Override

    public Map<R, V> column(C columnKey) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.column(columnKey);
    }

    @Override
    public Set<C> columnKeySet() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.columnKeySet();
    }

    @Override
    public Map<C, Map<R, V>> columnMap() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.columnMap();
    }

    assertEquals(ImmutableMap.of(), testTable.column(0));
    assertEquals(ImmutableMap.of('a', "blah"), testTable.column(1));
  }

  public void testColumnKeySet() {
    assertEquals(ImmutableSet.of(1), testTable.columnKeySet());
  }

  public void testColumnMap() {
    assertEquals(ImmutableMap.of(1, ImmutableMap.of('a', "blah")), testTable.columnMap());
  }

  public void testRow() {

    for (int i = 0; i < 5; i++) {
      table.put("r" + i, "c" + i, "v" + i);
    }
    assertThat(table.rowKeySet()).containsExactly("r0", "r1", "r2", "r3", "r4").inOrder();
    assertThat(table.columnKeySet()).containsExactly("c0", "c1", "c2", "c3", "c4").inOrder();
    assertThat(table.values()).containsExactly("v0", "v1", "v2", "v3", "v4").inOrder();
  }

  public void testCreateWithValidSizes() {

import java.util.Map;

/**
 * Implementation of {@link Table} using linked hash tables. This guarantees predictable iteration
 * order of the various views.
 *
 * <p>The views returned by {@link #column}, {@link #columnKeySet()}, and {@link #columnMap()} have
 * iterators that don't support {@code remove()}. Otherwise, all optional operations are supported.
 * Null row keys, columns keys, and values are not supported.
 *