val c = name[i]
    require(c in '\u0021'..'\u007e') {
      "Unexpected char 0x${c.charCode()} at $i in header name: $name"
    }
  }
}

internal fun headersCheckValue(
  value: String,
  name: String,
) {
  for (i in value.indices) {
    val c = value[i]
    require(c == '\t' || c in '\u0020'..'\u007e') {
      "Unexpected char 0x${c.charCode()} at $i in $name value" +

        assertEscaping(xmlEscaper, """, ch);
      } else {
        String input = String.valueOf(ch);
        String escaped = xmlEscaper.escape(input);
        assertWithMessage("char 0x" + Integer.toString(ch, 16) + " should not be escaped")
            .that(escaped)
            .isEqualTo(input);
      }
    }

    // Test that 0xFFFE and 0xFFFF are replaced with 0xFFFD

        assertEscaping(xmlEscaper, """, ch);
      } else {
        String input = String.valueOf(ch);
        String escaped = xmlEscaper.escape(input);
        assertWithMessage("char 0x" + Integer.toString(ch, 16) + " should not be escaped")
            .that(escaped)
            .isEqualTo(input);
      }
    }

    // Test that 0xFFFE and 0xFFFF are replaced with 0xFFFD

   *
   * <p>Accepts a decimal, hexadecimal, or octal number given by specifying the following prefix:
   *
   * <ul>
   *   <li>{@code 0x}<i>HexDigits</i>
   *   <li>{@code 0X}<i>HexDigits</i>
   *   <li>{@code #}<i>HexDigits</i>
   *   <li>{@code 0}<i>OctalDigits</i>
   * </ul>
   *

  }

  @GwtIncompatible // Doubles.tryParse
  public void testTryParseHex() {
    for (String signChar : ImmutableList.of("", "+", "-")) {
      for (String hexPrefix : ImmutableList.of("0x", "0X")) {
        for (String iPart : ImmutableList.of("", "0", "1", "F", "f", "c4", "CE")) {
          for (String fPart : ImmutableList.of("", ".", ".F", ".52", ".a")) {

  }

  @GwtIncompatible // Doubles.tryParse
  public void testTryParseHex() {
    for (String signChar : ImmutableList.of("", "+", "-")) {
      for (String hexPrefix : ImmutableList.of("0x", "0X")) {
        for (String iPart : ImmutableList.of("", "0", "1", "F", "f", "c4", "CE")) {
          for (String fPart : ImmutableList.of("", ".", ".F", ".52", ".a")) {

  }

  @GwtIncompatible // Floats.tryParse
  public void testTryParseHex() {
    for (String signChar : ImmutableList.of("", "+", "-")) {
      for (String hexPrefix : ImmutableList.of("0x", "0X")) {
        for (String iPart : ImmutableList.of("", "0", "1", "F", "f", "c4", "CE")) {
          for (String fPart : ImmutableList.of("", ".", ".F", ".52", ".a")) {

  }

  @GwtIncompatible // Floats.tryParse
  public void testTryParseHex() {
    for (String signChar : ImmutableList.of("", "+", "-")) {
      for (String hexPrefix : ImmutableList.of("0x", "0X")) {
        for (String iPart : ImmutableList.of("", "0", "1", "F", "f", "c4", "CE")) {
          for (String fPart : ImmutableList.of("", ".", ".F", ".52", ".a")) {

      if (ch > Ascii.MAX) {
        throw new DecodingException("Unrecognized character: 0x" + Integer.toHexString(ch));
      }
      int result = decodabet[ch];
      if (result == -1) {
        if (ch <= 0x20 || ch == Ascii.MAX) {
          throw new DecodingException("Unrecognized character: 0x" + Integer.toHexString(ch));
        } else {
          throw new DecodingException("Unrecognized character: " + ch);

<a href="#Constants">integer constant</a>.
An optional prefix sets a non-decimal base: <code>0b</code> or <code>0B</code>
for binary, <code>0</code>, <code>0o</code>, or <code>0O</code> for octal,
and <code>0x</code> or <code>0X</code> for hexadecimal
[<a href="#Go_1.13">Go 1.13</a>].
A single <code>0</code> is considered a decimal zero.
In hexadecimal literals, letters <code>a</code> through <code>f</code>