assertEquals("foobar", Ascii.toLowerCase("fOobaR"));
  }

  public void testToUpperCase() {
    assertEquals(UPPER, Ascii.toUpperCase(LOWER));
    assertSame(UPPER, Ascii.toUpperCase(UPPER));
    assertEquals(IGNORED, Ascii.toUpperCase(IGNORED));
    assertEquals("FOOBAR", Ascii.toUpperCase("FoOBAr"));
  }

  public void testCharsIgnored() {
    for (char c : IGNORED.toCharArray()) {
      String str = String.valueOf(c);

    assertEquals("foobar", Ascii.toLowerCase("fOobaR"));
  }

  public void testToUpperCase() {
    assertEquals(UPPER, Ascii.toUpperCase(LOWER));
    assertSame(UPPER, Ascii.toUpperCase(UPPER));
    assertEquals(IGNORED, Ascii.toUpperCase(IGNORED));
    assertEquals("FOOBAR", Ascii.toUpperCase("FoOBAr"));
  }

  public void testCharsIgnored() {
    for (char c : IGNORED.toCharArray()) {
      String str = String.valueOf(c);

  public void testMap() {
    SpliteratorTester.of(
            () ->
                CollectSpliterators.map(
                    Arrays.spliterator(new String[] {"a", "b", "c", "d", "e"}), Ascii::toUpperCase))
        .expect("A", "B", "C", "D", "E");
  }

  public void testFlatMap() {
    SpliteratorTester.of(
            () ->
                CollectSpliterators.flatMap(