val length0 = source.readByte().toInt() and 0xff
    val length =
      when {
        length0 == 0b1000_0000 -> {
          throw ProtocolException("indefinite length not permitted for DER")
        }
        (length0 and 0b1000_0000) == 0b1000_0000 -> {
          // Length specified over multiple bytes.
          val lengthBytes = length0 and 0b0111_1111
          if (lengthBytes > 8) {

    } else {
      // count how many bytes we'll need to express the length.
      val lengthBitCount = 64 - java.lang.Long.numberOfLeadingZeros(length)
      val lengthByteCount = (lengthBitCount + 7) / 8
      sink.writeByte(0b1000_0000 or lengthByteCount)
      for (shift in (lengthByteCount - 1) * 8 downTo 0 step 8) {
        sink.writeByte((length shr shift).toInt())
      }
    }

    // Write the payload.
    sink.writeAll(content)
  }

  /** Map pre-created before experiment starts to only measure iteration cost during experiment. */
  Map<Element, Element> map;

  CollectionBenchmarkSampleData elems;

  @Param({"0", "1", "100", "10000"})
  int elements;

  @BeforeExperiment
  public void prepareContents() throws Exception {
    mapsImpl = mapEnums.get(implName);
    elems = new CollectionBenchmarkSampleData(elements);

  }

  @Test fun `decode length overflowing Long`() {
    val buffer =
      Buffer()
        .writeByte(0b00000010)
        .writeByte(0b10001000)
        .writeByte(0b10000000)
        .writeByte(0b00000000)
        .writeByte(0b00000000)
        .writeByte(0b00000000)
        .writeByte(0b00000000)
        .writeByte(0b00000000)
        .writeByte(0b00000000)