internal fun Regex.matchAtPolyfill(
  input: CharSequence,
  index: Int,
): MatchResult? {
  val candidate = find(input, index) ?: return null
  if (candidate.range.first != index) return null // Didn't match where it should have.
  return candidate
}

@JvmField
val EMPTY_BYTE_ARRAY: ByteArray = ByteArray(0)

/** Byte order marks. */
internal val UNICODE_BOMS =

  }

  @Test
  fun clientCloseWith0Fails() {
    assertFailsWith<IllegalArgumentException> {
      client.webSocket!!.close(0, null)
    }.also { expected ->
      assertThat("Code must be in range [1000,5000): 0")
        .isEqualTo(expected.message)
    }
  }

  @Test
  fun afterSocketClosedPingFailsWebSocket() {
    client2Server.source.close()
    client.webSocket!!.pong("Ping!".encodeUtf8())

        }
        is MappedRange.Inline2 -> {
          rangesBuffer.writeByte(range.b1)
          rangesBuffer.writeByte(range.b2)
          rangesBuffer.writeByte(range.b3)
        }
        is MappedRange.InlineDelta -> {
          rangesBuffer.writeByte(range.b1)
          rangesBuffer.writeByte(range.b2)
          rangesBuffer.writeByte(range.b3)
        }
        is MappedRange.External -> {
          // Write the mapping.

      unassigned = unassigned,
      mapping = mapping,
      prohibitSet = prohibitSet,
      randalcatSet = randalcatSet,
      lcatSet = lcatSet,
    )
  }

  /**
   * Reads a set of range lines like the following:
   *
   * ```
   *  0221
   *  0234-024F
   *  0000-001F; [CONTROL CHARACTERS]
   *  007F; DELETE
   * ```
   */
  fun readCodePointSet(path: Path): RangeListCodePointSet {

          }
        expiresAt = currentTimeMillis + deltaMilliseconds
        if (expiresAt < currentTimeMillis || expiresAt > MAX_DATE) {
          expiresAt = MAX_DATE // Handle overflow & limit the date range.
        }
      }

      // If the domain is present, it must domain match. Otherwise we have a host-only cookie.
      val urlHost = url.host
      if (domain == null) {
        domain = urlHost

          keyIndex++
        }
      }
    } while (cursor.next() != -1)
  }

  fun closeCodeExceptionMessage(code: Int): String? {
    return if (code < 1000 || code >= 5000) {
      "Code must be in range [1000,5000): $code"
    } else if (code in 1004..1006 || code in 1015..2999) {
      "Code $code is reserved and may not be used."
    } else {
      null
    }
  }

  fun validateCloseCode(code: Int) {

    unstable and prone to native crashes in the underlying OpenSSL code.
 *  Fix: Don't send both `If-None-Match` and `If-Modified-Since` cache headers
    when both are applicable.
 *  Fix: Fail early when a port is out of range.
 *  Fix: Offer `Content-Length` headers for multipart request bodies.
 *  Fix: Throw `UnknownServiceException` if a cleartext connection is attempted
    when explicitly forbidden.

 * and the last 7 bits from this byte.
 *
 * The end of the range is not encoded, but can be inferred by looking at the start of the range
 * that follows.
 *
 * b1
 * --
 *
 * This is either a mapping decision or the length of the mapped output, according to this table:
 *
 * ```
 *  0..63 : Length of the UTF-16 sequence that this range maps to. The offset is b2b3.

  var s = typeSubtype.range.last + 1
  while (s < length) {
    val parameter = PARAMETER.matchAtPolyfill(this, s)
    require(parameter != null) {
      "Parameter is not formatted correctly: \"${substring(s)}\" for: \"$this\""
    }

    val name = parameter.groups[1]?.value
    if (name == null) {
      s = parameter.range.last + 1
      continue
    }

        when {
          r + 1 < rangesOffsets.size -> rangesOffsets[r + 1] * 4
          else -> rangesOffsets.size * 4
        }

      // Confirm this range starts with byte 0.
      assertThat(compactTable.ranges[rangePos].code).isEqualTo(0)

      // Confirm this range's index byte is increasing.
      val rangeStarts = mutableListOf<Int>()
      for (i in rangePos until rangeLimit step 4) {