r := rune(s[0])
		if r >= utf8.RuneSelf {
			// search utf8.RuneError.
			for _, r = range chars {
				if r == utf8.RuneError {
					return 0
				}
			}
			return -1
		}
		if bytealg.IndexByteString(chars, s[0]) >= 0 {
			return 0
		}
		return -1
	}
	if len(chars) == 1 {
		r := rune(chars[0])
		if r >= utf8.RuneSelf {
			r = utf8.RuneError
		}
		return IndexRune(s, r)

  // We can't use Character.isSurrogate(c) because of GWT.

  public void testEncodedLength_validStrings() {
    assertEquals(0, Utf8.encodedLength(""));
    assertEquals(11, Utf8.encodedLength("Hello world"));
    assertEquals(8, Utf8.encodedLength("Résumé"));
    assertEquals(
        461,
        Utf8.encodedLength(
            "威廉·莎士比亞（William Shakespeare，"
                + "1564年4月26號—1616年4月23號[1]）係隻英國嗰演員、劇作家同詩人，"

	if atEOF && len(data) == 0 {
		return 0, nil, nil
	}

	// Fast path 1: ASCII.
	if data[0] < utf8.RuneSelf {
		return 1, data[0:1], nil
	}

	// Fast path 2: Correct UTF-8 decode without error.
	_, width := utf8.DecodeRune(data)
	if width > 1 {
		// It's a valid encoding. Width cannot be one for a correctly encoded
		// non-ASCII rune.

func (b *Buffer) WriteRune(r rune) (n int, err error) {
	// Compare as uint32 to correctly handle negative runes.
	if uint32(r) < utf8.RuneSelf {
		b.WriteByte(byte(r))
		return 1, nil
	}
	b.lastRead = opInvalid
	m, ok := b.tryGrowByReslice(utf8.UTFMax)
	if !ok {
		m = b.grow(utf8.UTFMax)
	}
	b.buf = utf8.AppendRune(b.buf[:m], r)
	return len(b.buf) - m, nil
}

import (
	. "bufio"
	"bytes"
	"errors"
	"io"
	"strings"
	"testing"
	"unicode"
	"unicode/utf8"
)

const smallMaxTokenSize = 256 // Much smaller for more efficient testing.

// Test white space table matches the Unicode definition.
func TestSpace(t *testing.T) {
	for r := rune(0); r <= utf8.MaxRune; r++ {
		if IsSpace(r) != unicode.IsSpace(r) {

	}
}

func TestRuneIO(t *testing.T) {
	const NRune = 1000
	// Built a test slice while we write the data
	b := make([]byte, utf8.UTFMax*NRune)
	var buf Buffer
	n := 0
	for r := rune(0); r < NRune; r++ {
		size := utf8.EncodeRune(b[n:], r)
		nbytes, err := buf.WriteRune(r)
		if err != nil {
			t.Fatalf("WriteRune(%U) error: %s", r, err)
		}
		if nbytes != size {

		//
		// Forbid 0x7e and 0x5c since EUC-KR and Shift-JIS replace those
		// characters with localized currency and overline characters.
		if r < 0x20 || r > 0x7d || r == 0x5c {
			if !utf8.ValidRune(r) || (r == utf8.RuneError && size == 1) {
				return false, false
			}
			require = true
		}
	}
	return true, require
}

// prepare performs the bookkeeping operations required at the start of

func (b *Reader) ReadRune() (r rune, size int, err error) {
	for b.r+utf8.UTFMax > b.w && !utf8.FullRune(b.buf[b.r:b.w]) && b.err == nil && b.w-b.r < len(b.buf) {
		b.fill() // b.w-b.r < len(buf) => buffer is not full
	}
	b.lastRuneSize = -1
	if b.r == b.w {
		return 0, 0, b.readErr()
	}
	r, size = utf8.DecodeRune(b.buf[b.r:b.w])
	b.r += size
	b.lastByte = int(b.buf[b.r-1])
	b.lastRuneSize = size

    },
    PERCENT {
      override fun encode(codePoint: Int): String {
        val utf8 = IDENTITY.encode(codePoint).encodeUtf8()
        val percentEncoded = Buffer()
        for (i in 0 until utf8.size) {
          percentEncoded
            .writeUtf8("%")
            .writeUtf8(ByteString.of(utf8[i]).hex().uppercase())
        }
        return percentEncoded.readUtf8()
      }
    },

  return millis.toInt()
}

internal fun List<Header>.toHeaders(): Headers {
  val builder = Headers.Builder()
  for ((name, value) in this) {
    builder.addLenient(name.utf8(), value.utf8())
  }
  return builder.build()
}

internal fun Headers.toHeaderList(): List<Header> =
  (0 until size).map {
    Header(name(it), value(it))
  }