@Test
    public void testClear() throws Exception {
        map.clear();
        assertThat(map.size(), is(0));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testEntrySet() throws Exception {
        Iterator<Map.Entry<String, String>> i = map.entrySet().iterator();
        assertThat(i.next().getKey(), is(nullValue()));
        assertThat(i.next().getKey(), is("1"));

    // backward map ordered by country (even for currency values)
    assertThat(bimap.inverse().values()).containsExactly(Currency.DOLLAR, Currency.PESO).inOrder();
  }

  public void testEntrySet() {
    // Bug 3168290
    Map<Currency, Country> map =
        ImmutableMap.of(
            Currency.DOLLAR, Country.CANADA,
            Currency.PESO, Country.CHILE,

    } else {
      try {
        boolean unused2 = map.containsKey(null);
      } catch (NullPointerException optional) {
      }
    }
    assertInvariants(map);
  }

  public void testEntrySet() {
    Map<K, V> map;
    try {
      map = makePopulatedMap();
    } catch (UnsupportedOperationException e) {
      return;
    }
    assertInvariants(map);

    } else {
      try {
        boolean unused2 = map.containsKey(null);
      } catch (NullPointerException optional) {
      }
    }
    assertInvariants(map);
  }

  public void testEntrySet() {
    Map<K, V> map;
    try {
      map = makePopulatedMap();
    } catch (UnsupportedOperationException e) {
      return;
    }
    assertInvariants(map);