StringBuilder sb = new StringBuilder();
      for (int j = 0; j < charCount; j++) {
        int codePoint;
        // discard illegal surrogate "codepoints"
        do {
          codePoint = rnd.nextInt(maxCodePoint.value);
        } while (Character.isSurrogate((char) codePoint));
        sb.appendCodePoint(codePoint);
      }
      strings[i] = sb.toString();
    }
  }

  @Benchmark

import okio.Buffer
import okio.Path
import okio.Path.Companion.toPath

val okHttpRoot: Path
  get() = getEnv("OKHTTP_ROOT")!!.toPath()

fun String(vararg codePoints: Int): String {
  val buffer = Buffer()
  for (codePoint in codePoints) {
    buffer.writeUtf8CodePoint(codePoint)
  }
  return buffer.readUtf8()

    copyTo(prefix, 0, byteCount)
    for (i in 0 until 16) {
      if (prefix.exhausted()) {
        break
      }
      val codePoint = prefix.readUtf8CodePoint()
      if (Character.isISOControl(codePoint) && !Character.isWhitespace(codePoint)) {
        return false
      }
    }
    return true
  } catch (_: EOFException) {
    return false // Truncated UTF-8 sequence.
  }

    assertThat(formEncode(255)).isEqualTo("%C3%BF")
  }

  @Throws(IOException::class)
  private fun formEncode(codePoint: Int): String {
    // Wrap the codepoint with regular printable characters to prevent trimming.
    val body =
      FormBody.Builder()
        .add("a", String(intArrayOf('b'.code, codePoint, 'c'.code), 0, 3))
        .build()
    val buffer = Buffer()
    body.writeTo(buffer)

    for (int z = 0; z < 100; z++) {
      String str;
      int[] codePoints = new int[rng.nextInt(8)];
      for (int i = 0; i < codePoints.length; i++) {
        do {
          codePoints[i] = rng.nextInt(0x800);
        } while (!Character.isValidCodePoint(codePoints[i])
            || (codePoints[i] >= Character.MIN_SURROGATE
                && codePoints[i] <= Character.MAX_SURROGATE));
      }

    for (int z = 0; z < 100; z++) {
      String str;
      int[] codePoints = new int[rng.nextInt(8)];
      for (int i = 0; i < codePoints.length; i++) {
        do {
          codePoints[i] = rng.nextInt(0x800);
        } while (!Character.isValidCodePoint(codePoints[i])
            || (codePoints[i] >= Character.MIN_SURROGATE
                && codePoints[i] <= Character.MAX_SURROGATE));
      }

 */
internal fun inlineDeltaOrNull(mapping: Mapping): MappedRange.InlineDelta? {
  if (mapping.hasSingleSourceCodePoint) {
    val sourceCodePoint = mapping.sourceCodePoint0
    val mappedCodePoints = mapping.mappedTo.utf8().codePoints().toList()
    if (mappedCodePoints.size == 1) {
      val codePointDelta = mappedCodePoints.single() - sourceCodePoint
      if (MappedRange.InlineDelta.MAX_VALUE >= abs(codePointDelta)) {

        if (byte2 > (byte) 0xBF
            // Overlong? 5 most significant bits must not all be zero.
            || (byte1 == (byte) 0xE0 && byte2 < (byte) 0xA0)
            // Check for illegal surrogate codepoints.
            || (byte1 == (byte) 0xED && (byte) 0xA0 <= byte2)
            // Third byte trailing-byte test.
            || bytes[index++] > (byte) 0xBF) {
          return false;
        }
      } else {

        if (byte2 > (byte) 0xBF
            // Overlong? 5 most significant bits must not all be zero.
            || (byte1 == (byte) 0xE0 && byte2 < (byte) 0xA0)
            // Check for illegal surrogate codepoints.
            || (byte1 == (byte) 0xED && (byte) 0xA0 <= byte2)
            // Third byte trailing-byte test.
            || bytes[index++] > (byte) 0xBF) {
          return false;
        }
      } else {