}
    return builder.buildOrThrow();
  }

  // The bulk of the toImmutableTable tests can be found in TableCollectorsTest.
  // This gives minimal coverage to the forwarding functions
  public void testToImmutableTableSanityTest() {
    Collector<Cell<String, String, Integer>, ?, ImmutableTable<String, String, Integer>> collector =
        toImmutableTable(Cell::getRowKey, Cell::getColumnKey, Cell::getValue);
    CollectorTester.of(collector)