// This gives minimal coverage to the forwarding functions
  public void testToImmutableTableSanityTest() {
    Collector<Cell<String, String, Integer>, ?, ImmutableTable<String, String, Integer>> collector =
        TableCollectors.toImmutableTable(Cell::getRowKey, Cell::getColumnKey, Cell::getValue);
    CollectorTester.of(collector)
        .expectCollects(ImmutableTable.of())

    ImmutableTable.Builder<Character, Integer, String> builder = new ImmutableTable.Builder<>();

    final StringHolder holder = new StringHolder();
    holder.string = "foo";
    Table.Cell<Character, Integer, String> mutableCell =
        new Tables.AbstractCell<Character, Integer, String>() {
          @Override
          public Character getRowKey() {
            return 'K';
          }