@GwtCompatible
@IgnoreJRERequirement // used only from APIs with Java 8 types in them
final class TableCollectors {

  static <T extends @Nullable Object, R, C, V>
      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");

/** Collectors utilities for {@code common.collect.Table} internals. */
@GwtCompatible
final class TableCollectors {

  static <T extends @Nullable Object, R, C, V>
      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");

    }
    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)

   */
  public static <T extends @Nullable Object, R, C, V>
      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);
  }

  /**

  public static <T extends @Nullable Object, R, C, V>
      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);
  }

  /**

   * is thrown when the collection operation is performed.
   *
   * <p>To collect to an {@link ImmutableTable}, use {@link ImmutableTable#toImmutableTable}.
   *
   * @since 21.0
   */
  public static <
          T extends @Nullable Object,
          R extends @Nullable Object,
          C extends @Nullable Object,
          V,

   * is thrown when the collection operation is performed.
   *
   * <p>To collect to an {@link ImmutableTable}, use {@link ImmutableTable#toImmutableTable}.
   *
   * @since 33.2.0 (available since 21.0 in guava-jre)
   */
  @IgnoreJRERequirement // Users will use this only if they're already using streams.
  public static <
          T extends @Nullable Object,