assertMapEquals(copy, "one", 1, "two", 2, "three", 3);
    assertThat(ImmutableBiMap.copyOf(copy)).isSameInstanceAs(copy);
  }

  public void testEmpty() {
    ImmutableBiMap<String, Integer> bimap = ImmutableBiMap.of();
    assertEquals(Collections.<String, Integer>emptyMap(), bimap);
    assertEquals(Collections.<Integer, String>emptyMap(), bimap.inverse());
  }

    assertThat(ImmutableIntArray.of(0, 1, 3).subArray(1, 1).length()).isEqualTo(0);
    assertThat(ImmutableIntArray.of(0, 1, 3).subArray(1, 2).length()).isEqualTo(1);
  }

  public void testIsEmpty() {
    assertThat(ImmutableIntArray.of().isEmpty()).isTrue();
    assertThat(ImmutableIntArray.of(0).isEmpty()).isFalse();
    assertThat(ImmutableIntArray.of(0, 1, 3).isEmpty()).isFalse();

    assertThat(ImmutableDoubleArray.of(0, 1, 3).subArray(1, 1).length()).isEqualTo(0);
    assertThat(ImmutableDoubleArray.of(0, 1, 3).subArray(1, 2).length()).isEqualTo(1);
  }

  public void testIsEmpty() {
    assertThat(ImmutableDoubleArray.of().isEmpty()).isTrue();
    assertThat(ImmutableDoubleArray.of(0).isEmpty()).isFalse();
    assertThat(ImmutableDoubleArray.of(0, 1, 3).isEmpty()).isFalse();

    assertThat(ImmutableIntArray.of(0, 1, 3).subArray(1, 1).length()).isEqualTo(0);
    assertThat(ImmutableIntArray.of(0, 1, 3).subArray(1, 2).length()).isEqualTo(1);
  }

  public void testIsEmpty() {
    assertThat(ImmutableIntArray.of().isEmpty()).isTrue();
    assertThat(ImmutableIntArray.of(0).isEmpty()).isFalse();
    assertThat(ImmutableIntArray.of(0, 1, 3).isEmpty()).isFalse();

    assertThat(ImmutableDoubleArray.of(0, 1, 3).subArray(1, 1).length()).isEqualTo(0);
    assertThat(ImmutableDoubleArray.of(0, 1, 3).subArray(1, 2).length()).isEqualTo(1);
  }

  public void testIsEmpty() {
    assertThat(ImmutableDoubleArray.of().isEmpty()).isTrue();
    assertThat(ImmutableDoubleArray.of(0).isEmpty()).isFalse();
    assertThat(ImmutableDoubleArray.of(0, 1, 3).isEmpty()).isFalse();

    matcher.setBits(bitset);
    for (int i = Character.MIN_VALUE; i <= Character.MAX_VALUE; i++) {
      assertEquals(matcher.matches((char) i), bitset.get(i));
    }
  }

  public void testEmpty() throws Exception {
    doTestEmpty(CharMatcher.any());
    doTestEmpty(CharMatcher.none());
    doTestEmpty(is('a'));
    doTestEmpty(isNot('a'));
    doTestEmpty(anyOf(""));
    doTestEmpty(anyOf("x"));

  }

  public void testLimit_illegalArgument() {
    List<String> list = newArrayList("a", "b", "c");
    assertThrows(IllegalArgumentException.class, () -> Iterables.limit(list, -1));
  }

  public void testIsEmpty() {
    Iterable<String> emptyList = emptyList();
    assertTrue(Iterables.isEmpty(emptyList));

    Iterable<String> singletonList = singletonList("foo");
    assertFalse(Iterables.isEmpty(singletonList));
  }