private static long codePointToFourUtf8Bytes(int codePoint) {
    // codePoint has at most 21 bits
    return ((0xFL << 4) | (codePoint >>> 18))
        | ((0x80L | (0x3F & (codePoint >>> 12))) << 8)
        | ((0x80L | (0x3F & (codePoint >>> 6))) << 16)
        | ((0x80L | (0x3F & codePoint)) << 24);
  }

  private static long charToThreeUtf8Bytes(char c) {
    return ((0x7L << 5) | (c >>> 12))

  private static long codePointToFourUtf8Bytes(int codePoint) {
    // codePoint has at most 21 bits
    return ((0xFL << 4) | (codePoint >>> 18))
        | ((0x80L | (0x3F & (codePoint >>> 12))) << 8)
        | ((0x80L | (0x3F & (codePoint >>> 6))) << 16)
        | ((0x80L | (0x3F & codePoint)) << 24);
  }

  private static long charToThreeUtf8Bytes(char c) {
    return ((0x7L << 5) | (c >>> 12))

          continue
        }
        testEncodeAndDecode(codePoint, codePointString, component)
        if (encoding == Encoding.SKIP) continue
        testParseOriginal(codePoint, codePointString, encoding, component)
        testParseAlreadyEncoded(codePoint, encoding, component)

        val platform = urlComponentEncodingTesterJvmPlatform(component)
        platform.test(codePoint, codePointString, encoding, component)
      }
    }

  val bufferA = Buffer().writeUtf8(host)
  val bufferB = Buffer()

  // 1. Map, from bufferA to bufferB.
  while (!bufferA.exhausted()) {
    val codePoint = bufferA.readUtf8CodePoint()
    if (!IDNA_MAPPING_TABLE.map(codePoint, bufferB)) return null
  }

  // 2. Normalize, from bufferB to bufferA.
  val normalized = normalizeNfc(bufferB.readUtf8())
  bufferA.writeUtf8(normalized)

    }
    return new String(dest, 0, destIndex);
  }

  /**
   * Returns the Unicode code point of the character at the given index.
   *
   * <p>Unlike {@link Character#codePointAt(CharSequence, int)} or {@link String#codePointAt(int)}
   * this method will never fail silently when encountering an invalid surrogate pair.
   *
   * <p>The behaviour of this method is as follows:
   *
   * <ol>

    }
    return new String(dest, 0, destIndex);
  }

  /**
   * Returns the Unicode code point of the character at the given index.
   *
   * <p>Unlike {@link Character#codePointAt(CharSequence, int)} or {@link String#codePointAt(int)}
   * this method will never fail silently when encountering an invalid surrogate pair.
   *
   * <p>The behaviour of this method is as follows:
   *
   * <ol>

    utf8Lengths.put(MAX_CODE_POINT, 4);

    Integer[] codePoints = utf8Lengths.keySet().toArray(new Integer[] {});
    StringBuilder sb = new StringBuilder();
    Random rnd = new Random();
    for (int trial = 0; trial < 100; trial++) {
      sb.setLength(0);
      int utf8Length = 0;
      for (int i = 0; i < 6; i++) {
        Integer randomCodePoint = codePoints[rnd.nextInt(codePoints.length)];
        sb.appendCodePoint(randomCodePoint);