assertThat(table.row('c').keySet()).containsExactly(0, 3).inOrder();
    assertThat(table.column(5).keySet()).containsExactly('e', 'x').inOrder();
  }

  public void testBuilder_orderRowsAndColumnsBy_dense() {
    ImmutableTable.Builder<Character, Integer, String> builder = ImmutableTable.builder();
    builder.orderRowsBy(Ordering.natural());
    builder.orderColumnsBy(Ordering.natural());
    builder.put('c', 3, "foo");

  private static final DenseImmutableTable<Character, Integer, String> DENSE =
      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() {

import com.google.j2objc.annotations.WeakOuter;
import java.util.Map;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/** A {@code RegularImmutableTable} optimized for dense data. */
@GwtCompatible
@Immutable(containerOf = {"R", "C", "V"})
@ElementTypesAreNonnullByDefault
final class DenseImmutableTable<R, C, V> extends RegularImmutableTable<R, C, V> {

  private static final DenseImmutableTable<Character, Integer, String> DENSE =
      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() {

  static <R, C, V> RegularImmutableTable<R, C, V> forOrderedComponents(
      ImmutableList<Cell<R, C, V>> cellList,
      ImmutableSet<R> rowSpace,
      ImmutableSet<C> columnSpace) {
    // use a dense table if more than half of the cells have values
    // TODO(gak): tune this condition based on empirical evidence
    return (cellList.size() > (((long) rowSpace.size() * columnSpace.size()) / 2))

    assertThat(table.row('c').keySet()).containsExactly(0, 3).inOrder();
    assertThat(table.column(5).keySet()).containsExactly('e', 'x').inOrder();
  }

  public void testBuilder_orderRowsAndColumnsBy_dense() {
    ImmutableTable.Builder<Character, Integer, String> builder = ImmutableTable.builder();
    builder.orderRowsBy(Ordering.natural());
    builder.orderColumnsBy(Ordering.natural());
    builder.put('c', 3, "foo");

import com.google.j2objc.annotations.WeakOuter;
import java.util.Map;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/** A {@code RegularImmutableTable} optimized for dense data. */
@GwtCompatible
@Immutable(containerOf = {"R", "C", "V"})
@ElementTypesAreNonnullByDefault
final class DenseImmutableTable<R, C, V> extends RegularImmutableTable<R, C, V> {

 * Second, it is always backed by an array large enough to hold a value for every possible
 * combination of row and column keys. (This is rarely optimal unless the table is extremely dense.)
 * Finally, every possible combination of row and column keys is always considered to have a value
 * associated with it: It is not possible to "remove" a value, only to replace it with {@code null},

   *       in the {@code exceptions} collection.
   * </ul>
   *
   * <p>Though this method takes any {@link Collection}, it often makes most sense to pass a {@link
   * java.util.List} or some other collection that preserves the order in which the exceptions got
   * added.
   *
   * @throws NullPointerException if {@code exceptions} is null

    }

    /**
     * Throws {@link UnsupportedOperationException}. This method is inherited from {@link
     * ImmutableMap.Builder}, but it does not make sense for bimaps.
     *
     * @throws UnsupportedOperationException always
     * @deprecated This method does not make sense for bimaps and should not be called.
     * @since 31.1
     */
    @DoNotCall
    @Deprecated
    @Override