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(str, c, Ascii.toLowerCase(c));
      assertEquals(str, c, Ascii.toUpperCase(c));