import java.util.HashMap;

/**
 * GWT emulation of {@link RegularImmutableBiMap}.
 *
 * @author Jared Levy
 * @author Hayward Chan
 */
@SuppressWarnings("serial")
final class RegularImmutableBiMap<K, V> extends ImmutableBiMap<K, V> {
  static final RegularImmutableBiMap<Object, Object> EMPTY =
      new RegularImmutableBiMap<Object, Object>();

  private final transient ImmutableBiMap<V, K> inverse;

 */
@GwtCompatible
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
final class RegularImmutableBiMap<K, V> extends ImmutableBiMap<K, V> {
  @SuppressWarnings("unchecked") // TODO(cpovirk): Consider storing Entry<?, ?>[] instead.
  static final RegularImmutableBiMap<Object, Object> EMPTY =
      new RegularImmutableBiMap<>(
          null, null, (Entry<Object, Object>[]) ImmutableMap.EMPTY_ENTRY_ARRAY, 0, 0);

    for (int i = 0; i < 10; i++) {
      builder.put(i, i);
    }
    Object[] builderArrayAfterPuts = builder.alternatingKeysAndValues;
    RegularImmutableBiMap<Integer, Integer> map =
        (RegularImmutableBiMap<Integer, Integer>) builder.build();
    Object[] mapInternalArray = map.alternatingKeysAndValues;
    assertThat(builderArrayAfterPuts).isSameInstanceAs(builderArray);