*/
    protected Maps(final Map<K, V> map) {
        this.map = map;
    }

    /**
     * {@link Map}にキーと値を追加します。
     *
     * @param key
     *            <code>Map</code>に追加されるキー
     * @param value
     *            <code>Map</code>に追加される値
     * @return このインスタンス自身
     */
    public Maps<K, V> $(final K key, final V value) {
        map.put(key, value);
        return this;

      implements MapDifference<K, V> {
    final Map<K, V> onlyOnLeft;
    final Map<K, V> onlyOnRight;
    final Map<K, V> onBoth;
    final Map<K, ValueDifference<V>> differences;

    MapDifferenceImpl(
        Map<K, V> onlyOnLeft,
        Map<K, V> onlyOnRight,
        Map<K, V> onBoth,
        Map<K, ValueDifference<V>> differences) {
      this.onlyOnLeft = unmodifiableMap(onlyOnLeft);

    Map<String, Integer> equalToUnderlying = Maps.newTreeMap();
    equalToUnderlying.putAll(underlying);
    Map<String, Integer> map =
        Maps.transformValues(equalToUnderlying, Functions.<Integer>identity());
    assertMapsEqual(expected, map);

    map =
        Maps.transformValues(
            ImmutableMap.of("a", 1, "b", 2, "c", 3),
            new Function<Integer, Integer>() {

    TreeMap<Integer, Integer> map = Maps.newTreeMap(SOME_COMPARATOR);
    assertEquals(Collections.emptyMap(), map);
    assertSame(SOME_COMPARATOR, map.comparator());
  }

  public void testTreeMapWithInitialMap() {
    SortedMap<Integer, Integer> map = Maps.newTreeMap();
    map.put(5, 10);
    map.put(3, 20);
    map.put(1, 30);
    TreeMap<Integer, Integer> copy = Maps.newTreeMap(map);
    assertEquals(copy, map);

    TreeMap<Integer, Integer> map = Maps.newTreeMap(SOME_COMPARATOR);
    assertEquals(Collections.emptyMap(), map);
    assertSame(SOME_COMPARATOR, map.comparator());
  }

  public void testTreeMapWithInitialMap() {
    SortedMap<Integer, Integer> map = Maps.newTreeMap();
    map.put(5, 10);
    map.put(3, 20);
    map.put(1, 30);
    TreeMap<Integer, Integer> copy = Maps.newTreeMap(map);
    assertEquals(copy, map);

                  @Override
                  protected Map<String, String> create(Entry<String, String>[] entries) {
                    Map<String, String> map = Maps.newHashMap();
                    putEntries(map, entries);
                    map.putAll(ENTRIES_TO_FILTER);
                    map = Maps.filterEntries(map, FILTER_ENTRIES_1);
                    return Maps.filterEntries(map, FILTER_ENTRIES_2);
                  }

    public SampleElements<Entry<Country, String>> samples() {
      return new SampleElements<>(
          Maps.immutableEntry(Country.CANADA, "DOLLAR"),
          Maps.immutableEntry(Country.CHILE, "PESO"),
          Maps.immutableEntry(Country.UK, "POUND"),
          Maps.immutableEntry(Country.JAPAN, "YEN"),
          Maps.immutableEntry(Country.SWITZERLAND, "FRANC"));
    }

    @SuppressWarnings("unchecked")
    @Override

  SortedMap<String, Integer> createUnfiltered() {
    return Maps.newTreeMap();
  }

  public void testFirstAndLastKeyFilteredMap() {
    SortedMap<String, Integer> unfiltered = createUnfiltered();
    unfiltered.put("apple", 2);
    unfiltered.put("banana", 6);
    unfiltered.put("cat", 3);
    unfiltered.put("dog", 5);

    SortedMap<String, Integer> filtered = Maps.filterEntries(unfiltered, CORRECT_LENGTH);

import com.google.common.base.Functions;
import java.util.Map;

/**
 * Tests for {@link Maps#transformValues(Map, Function)}.
 *
 * @author Isaac Shum
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public class MapsTransformValuesTest extends AbstractMapsTransformValuesTest {
  @Override
  protected Map<String, String> makeEmptyMap() {
    return Maps.transformValues(Maps.<String, String>newHashMap(), Functions.<String>identity());

    Map<String, Integer> equalToUnderlying = Maps.newTreeMap();
    equalToUnderlying.putAll(underlying);
    Map<String, Integer> map =
        Maps.transformValues(equalToUnderlying, Functions.<Integer>identity());
    assertMapsEqual(expected, map);

    map =
        Maps.transformValues(
            ImmutableMap.of("a", 1, "b", 2, "c", 3),
            new Function<Integer, Integer>() {