EnumBiMap<Currency, Country> bimap2 = EnumBiMap.create(bimap1);
    assertEquals(Country.CANADA, bimap2.get(Currency.DOLLAR));
    assertEquals(bimap1, bimap2);
    bimap2.inverse().put(Country.SWITZERLAND, Currency.FRANC);
    assertEquals(Country.SWITZERLAND, bimap2.get(Currency.FRANC));
    assertThat(bimap1.get(Currency.FRANC)).isNull();
    assertFalse(bimap2.equals(bimap1));

    /* Test that it can be empty. */

    EnumBiMap<Currency, Country> bimap1 = EnumBiMap.create(Currency.class, Country.class);
    bimap1.put(Currency.DOLLAR, Country.SWITZERLAND);
    EnumHashBiMap<Currency, Object> bimap2 = // use supertype
        EnumHashBiMap.<Currency, Object>create(bimap1);
    assertEquals(Country.SWITZERLAND, bimap2.get(Currency.DOLLAR));
    assertEquals(bimap1, bimap2);
    bimap2.inverse().put("franc", Currency.FRANC);

    EnumBiMap<Currency, Country> bimap1 = EnumBiMap.create(Currency.class, Country.class);
    bimap1.put(Currency.DOLLAR, Country.SWITZERLAND);
    EnumHashBiMap<Currency, Object> bimap2 = // use supertype
        EnumHashBiMap.<Currency, Object>create(bimap1);
    assertEquals(Country.SWITZERLAND, bimap2.get(Currency.DOLLAR));
    assertEquals(bimap1, bimap2);
    bimap2.inverse().put("franc", Currency.FRANC);

  }

  public void testMapConstructor() {
    /* Test with non-empty Map. */
    Map<String, String> map =
        ImmutableMap.of(
            "canada", "dollar",
            "chile", "peso",
            "switzerland", "franc");
    HashBiMap<String, String> bimap = HashBiMap.create(map);
    assertThat(bimap.get("canada")).isEqualTo("dollar");
    assertThat(bimap.inverse().get("dollar")).isEqualTo("canada");
  }

  }

  public void testMapConstructor() {
    /* Test with non-empty Map. */
    Map<String, String> map =
        ImmutableMap.of(
            "canada", "dollar",
            "chile", "peso",
            "switzerland", "franc");
    HashBiMap<String, String> bimap = HashBiMap.create(map);
    assertThat(bimap.get("canada")).isEqualTo("dollar");
    assertThat(bimap.inverse().get("dollar")).isEqualTo("canada");
  }