assertEquals(LOWER, Ascii.toLowerCase(UPPER));
    assertSame(LOWER, Ascii.toLowerCase(LOWER));
    assertEquals(IGNORED, Ascii.toLowerCase(IGNORED));
    assertEquals("foobar", Ascii.toLowerCase("fOobaR"));
  }

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

    assertEquals(LOWER, Ascii.toLowerCase(UPPER));
    assertSame(LOWER, Ascii.toLowerCase(LOWER));
    assertEquals(IGNORED, Ascii.toLowerCase(IGNORED));
    assertEquals("foobar", Ascii.toLowerCase("fOobaR"));
  }

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

  }

  public void testToString() throws IOException {
    File asciiFile = getTestFile("ascii.txt");
    File i18nFile = getTestFile("i18n.txt");
    assertEquals(ASCII, Files.toString(asciiFile, Charsets.US_ASCII));
    assertEquals(I18N, Files.toString(i18nFile, Charsets.UTF_8));
    assertThat(Files.toString(i18nFile, Charsets.US_ASCII)).isNotEqualTo(I18N);
  }

  public void testWriteString() throws IOException {

  public void testWhyUsAsciiIsDangerous() {
    byte[] b1 = "朝日新聞".getBytes(Charsets.US_ASCII);
    byte[] b2 = "聞朝日新".getBytes(Charsets.US_ASCII);
    byte[] b3 = "????".getBytes(Charsets.US_ASCII);
    byte[] b4 = "ニュース".getBytes(Charsets.US_ASCII);
    byte[] b5 = "スューー".getBytes(Charsets.US_ASCII);
    // Assert they are all equal (using the transitive property)
    assertTrue(Arrays.equals(b1, b2));

  private Charsets() {}

  /**
   * US-ASCII: seven-bit ASCII, the Basic Latin block of the Unicode character set (ISO646-US).
   *
   * <p><b>Java 7+ users:</b> this constant should be treated as deprecated; use {@link
   * java.nio.charset.StandardCharsets#US_ASCII} instead.
   *
   */
  @J2ktIncompatible
  @GwtIncompatible // Charset not supported by GWT
  public static final Charset US_ASCII = Charset.forName("US-ASCII");

  /**

  public void testWhyUsAsciiIsDangerous() {
    byte[] b1 = "朝日新聞".getBytes(Charsets.US_ASCII);
    byte[] b2 = "聞朝日新".getBytes(Charsets.US_ASCII);
    byte[] b3 = "????".getBytes(Charsets.US_ASCII);
    byte[] b4 = "ニュース".getBytes(Charsets.US_ASCII);
    byte[] b5 = "スューー".getBytes(Charsets.US_ASCII);
    // Assert they are all equal (using the transitive property)
    assertTrue(Arrays.equals(b1, b2));

  private Charsets() {}

  /**
   * US-ASCII: seven-bit ASCII, the Basic Latin block of the Unicode character set (ISO646-US).
   *
   * <p><b>Java 7+ users:</b> this constant should be treated as deprecated; use {@link
   * java.nio.charset.StandardCharsets#US_ASCII} instead.
   *
   */
  @J2ktIncompatible
  @GwtIncompatible // Charset not supported by GWT
  public static final Charset US_ASCII = Charset.forName("US-ASCII");

  /**

    }


    @Test
    public void testAES256Checksum () throws GeneralSecurityException {
        String data = "fourteen";
        String key = "B1AE4CD8462AFF1677053CC9279AAC30B796FB81CE21474DD3DDBCFEA4EC76D7";
        String expect = "E08739E3279E2903EC8E3836";
        verifyAESHMAC(4, expect, key, data.getBytes(StandardCharsets.US_ASCII));
    }


    /**

    )
    assertEquals(
      "US-ASCII",
      noCharset.charset(Charsets.US_ASCII)!!.name(),
    )
    val charset = parse("text/plain; charset=iso-8859-1")
    assertEquals(
      "ISO-8859-1",
      charset.charset(Charsets.UTF_8)!!.name(),
    )
    assertEquals(
      "ISO-8859-1",
      charset.charset(Charsets.US_ASCII)!!.name(),
    )
  }

  @Test fun testTurkishDotlessIWithEnUs() {

    StringBuilder builder = new StringBuilder();
    long copied =
        CharStreams.copy(
            wrapAsGenericReadable(new StringReader(ASCII)), wrapAsGenericAppendable(builder));
    assertEquals(ASCII, builder.toString());
    assertEquals(ASCII.length(), copied);

    StringBuilder builder2 = new StringBuilder();
    copied =
        CharStreams.copy(