toImmutableTable(Cell::getRowKey, Cell::getColumnKey, Cell::getValue);
    BiPredicate<ImmutableTable<String, String, Integer>, ImmutableTable<String, String, Integer>>
        equivalence = pairwiseOnResultOf(ImmutableTable::cellSet);
    CollectorTester.of(collector, equivalence)
        .expectCollects(
            new ImmutableTable.Builder<String, String, Integer>()
                .put("one", "uno", 1)