Collector<T, ?, ImmutableTable<R, C, V>> toImmutableTable(
          Function<? super T, ? extends R> rowFunction,
          Function<? super T, ? extends C> columnFunction,
          Function<? super T, ? extends V> valueFunction) {
    checkNotNull(rowFunction, "rowFunction");
    checkNotNull(columnFunction, "columnFunction");
    checkNotNull(valueFunction, "valueFunction");
    return Collector.of(

      Collector<T, ?, ImmutableTable<R, C, V>> toImmutableTable(
          Function<? super T, ? extends R> rowFunction,
          Function<? super T, ? extends C> columnFunction,
          Function<? super T, ? extends V> valueFunction) {
    checkNotNull(rowFunction, "rowFunction");
    checkNotNull(columnFunction, "columnFunction");
    checkNotNull(valueFunction, "valueFunction");
    return Collector.of(

      Collector<T, ?, ImmutableTable<R, C, V>> toImmutableTable(
          Function<? super T, ? extends R> rowFunction,
          Function<? super T, ? extends C> columnFunction,
          Function<? super T, ? extends V> valueFunction) {
    return TableCollectors.toImmutableTable(rowFunction, columnFunction, valueFunction);
  }

  /**

          java.util.function.Function<? super T, ? extends R> rowFunction,
          java.util.function.Function<? super T, ? extends C> columnFunction,
          java.util.function.Function<? super T, ? extends V> valueFunction,
          java.util.function.Supplier<I> tableSupplier) {
    return TableCollectors.<T, R, C, V, I>toTable(
        rowFunction, columnFunction, valueFunction, tableSupplier);
  }

  /**

      Collector<T, ?, ImmutableTable<R, C, V>> toImmutableTable(
          Function<? super T, ? extends R> rowFunction,
          Function<? super T, ? extends C> columnFunction,
          Function<? super T, ? extends V> valueFunction) {
    return TableCollectors.toImmutableTable(rowFunction, columnFunction, valueFunction);
  }

  /**

        () ->
            Stream.of(immutableCell("one", "uno", 1), immutableCell("one", "uno", 2))
                .collect(collector));
  }

  // https://youtrack.jetbrains.com/issue/KT-58242/. Crash when rowFunction result (null) is unboxed
  @J2ktIncompatible
  public void testToImmutableTableNullRowKey() {
    Collector<Cell<String, String, Integer>, ?, ImmutableTable<String, String, Integer>> collector =