EnumHashBiMap<Currency, Country> bimap2 = EnumHashBiMap.create(emptyBimap2);
    assertTrue(bimap2.isEmpty());
  }

  public void testEnumHashBiMapConstructor() {
    /* Test that it copies existing entries. */
    EnumHashBiMap<Currency, String> bimap1 = EnumHashBiMap.create(Currency.class);
    bimap1.put(Currency.DOLLAR, "dollar");