}

  public void testIsEmpty() {
    assertTrue(INSTANCE.isEmpty());
  }

  public void testCellSet() {
    assertEquals(ImmutableSet.of(), INSTANCE.cellSet());
  }

  public void testColumn() {
    assertEquals(ImmutableMap.of(), INSTANCE.column(1));
  }

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

  public void testColumnMap() {

    assertEquals(Objects.hashCode('a', 1, "blah"), testTable.hashCode());
  }

  public void testCellSet() {
    assertEquals(ImmutableSet.of(immutableCell('a', 1, "blah")), testTable.cellSet());
  }

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

  public void testColumnKeySet() {

      assertEquals("baz", testInstance.get('a', 2));
      assertNull(testInstance.get('b', 2));
      assertNull(testInstance.get('c', 3));
    }
  }

  public void testColumn() {
    for (ImmutableTable<Character, Integer, String> testInstance : getTestInstances()) {
      assertEquals(ImmutableMap.of('a', "foo", 'b', "bar"), testInstance.column(1));

  public void testRowNull() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    assertThrows(NullPointerException.class, () -> table.row(null));
  }

  public void testColumn() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    assertEquals(ImmutableMap.of("foo", 'a', "bar", 'b'), table.column(1));
  }

  public void testRowNull() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    assertThrows(NullPointerException.class, () -> table.row(null));
  }

  public void testColumn() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    assertEquals(ImmutableMap.of("foo", 'a', "bar", 'b'), table.column(1));
  }