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