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));

  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");

  /**

  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");

  /**

    )
    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() {

// given ASCII character in the set. The 128-bits of the lower 16 bytes,
// starting with the least-significant bit of the lowest word to the
// most-significant bit of the highest word, map to the full range of all
// 128 ASCII characters. The 128-bits of the upper 16 bytes will be zeroed,
// ensuring that any non-ASCII character will be reported as not in the set.

   * This is like [toLowerCase] except that it does nothing if this contains any non-ASCII
   * characters. We want to avoid lower casing special chars like U+212A (Kelvin symbol) because
   * they can return ASCII characters that match real hostnames.
   */
  private fun String.asciiToLowercase(): String {
    return when {
      isAscii() -> lowercase(Locale.US) // This is an ASCII string.
      else -> this
    }
  }

          }
        };
    EscaperAsserts.assertBasic(deletingEscaper);
    assertEquals(
        "Everything outside the printable ASCII range is deleted.",
        deletingEscaper.escape(
            "\tEverything\0 outside the\uD800\uDC00 "
                + "printable ASCII \uFFFFrange is \u007Fdeleted.\n"));
  }

  public void testReplacementPriority() throws IOException {
    CharEscaper replacingEscaper =

internal object DnsRecordCodec {
  private const val SERVFAIL = 2
  private const val NXDOMAIN = 3
  const val TYPE_A = 0x0001
  const val TYPE_AAAA = 0x001c
  private const val TYPE_PTR = 0x000c
  private val ASCII = Charsets.US_ASCII

  fun encodeQuery(
    host: String,
    type: Int,
  ): ByteString =
    Buffer().apply {
      writeShort(0) // query id
      writeShort(256) // flags with recursion

   *
   * <p>This method accepts non-ASCII digits, for example {@code "１９２.１６８.０.１"} (those are fullwidth
   * characters). That is consistent with {@link InetAddress}, but not with various RFCs. If you
   * want to accept ASCII digits only, you can use something like {@code
   * CharMatcher.ascii().matchesAllOf(ipString)}.
   *