* undocumented and subject to change.
   */
  public static <R, C, V> ImmutableTable<R, C, V> copyOf(
      Table<? extends R, ? extends C, ? extends V> table) {
    if (table instanceof ImmutableTable) {
      @SuppressWarnings("unchecked")
      ImmutableTable<R, C, V> parameterizedTable = (ImmutableTable<R, C, V>) table;
      return parameterizedTable;
    } else {
      return copyOf(table.cellSet());

   * undocumented and subject to change.
   */
  public static <R, C, V> ImmutableTable<R, C, V> copyOf(
      Table<? extends R, ? extends C, ? extends V> table) {
    if (table instanceof ImmutableTable) {
      @SuppressWarnings("unchecked")
      ImmutableTable<R, C, V> parameterizedTable = (ImmutableTable<R, C, V>) table;
      return parameterizedTable;
    } else {
      return copyOf(table.cellSet());

  public void testToImmutableTable() {
    Collector<Cell<String, String, Integer>, ?, ImmutableTable<String, String, Integer>> collector =
        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(

    return Collector.of(
        (Supplier<ImmutableTable.Builder<R, C, V>>) ImmutableTable.Builder::new,
        (builder, t) ->
            builder.put(rowFunction.apply(t), columnFunction.apply(t), valueFunction.apply(t)),
        ImmutableTable.Builder::combine,
        ImmutableTable.Builder::buildOrThrow);
  }

  static <T extends @Nullable Object, R, C, V>
      Collector<T, ?, ImmutableTable<R, C, V>> toImmutableTable(

          .put(BiMap.class, ImmutableBiMap.of())
          .put(ImmutableBiMap.class, ImmutableBiMap.of())
          .put(Table.class, ImmutableTable.of())
          .put(ImmutableTable.class, ImmutableTable.of())
          .put(RowSortedTable.class, Tables.unmodifiableRowSortedTable(TreeBasedTable.create()))
          .put(ClassToInstanceMap.class, ImmutableClassToInstanceMap.builder().build())

      new DenseImmutableTable<>(CELLS.asList(), ROW_SPACE, COLUMN_SPACE);

  @Override
  Iterable<ImmutableTable<Character, Integer, String>> getTestInstances() {
    return ImmutableList.<ImmutableTable<Character, Integer, String>>of(SPARSE, DENSE);
  }

  public void testCellSet() {
    for (ImmutableTable<Character, Integer, String> testInstance : getTestInstances()) {
      assertEquals(CELLS, testInstance.cellSet());
    }

    }
  }

  private static final class MockEquivalence extends Equivalence<Object> {
    final ImmutableTable.Builder<Object, Object, Boolean> equivalentExpectationsBuilder =
        ImmutableTable.builder();
    final ImmutableMap.Builder<Object, Integer> hashExpectationsBuilder = ImmutableMap.builder();
    ImmutableTable<Object, Object, Boolean> equivalentExpectations;
    ImmutableMap<Object, Integer> hashExpectations;

    }
  }

  private static final class MockEquivalence extends Equivalence<Object> {
    final ImmutableTable.Builder<Object, Object, Boolean> equivalentExpectationsBuilder =
        ImmutableTable.builder();
    final ImmutableMap.Builder<Object, Integer> hashExpectationsBuilder = ImmutableMap.builder();
    ImmutableTable<Object, Object, Boolean> equivalentExpectations;
    ImmutableMap<Object, Integer> hashExpectations;

    return Collector.of(
        (Supplier<ImmutableTable.Builder<R, C, V>>) ImmutableTable.Builder::new,
        (builder, t) ->
            builder.put(rowFunction.apply(t), columnFunction.apply(t), valueFunction.apply(t)),
        ImmutableTable.Builder::combine,
        ImmutableTable.Builder::buildOrThrow);
  }

  static <T extends @Nullable Object, R, C, V>
      Collector<T, ?, ImmutableTable<R, C, V>> toImmutableTable(

import com.google.common.annotations.J2ktIncompatible;
import java.util.Map;

/**
 * An implementation of {@link ImmutableTable} that holds a single cell.
 *
 * @author Gregory Kick
 */
@GwtCompatible
final class SingletonImmutableTable<R, C, V> extends ImmutableTable<R, C, V> {
  final R singleRowKey;
  final C singleColumnKey;
  final V singleValue;