while (byteCount < limit) {
      result = result shl 8
      result += source.readByte().toInt() and 0xff
    }
    return result
  }

  fun readBitString(): BitString {
    if (bytesLeft == -1L || constructed) {
      throw ProtocolException("constructed bit strings not supported for DER")
    }
    if (bytesLeft < 1) {

        .write("0307040A3B5F291CD0".decodeHex())

    val derReader = DerReader(buffer)

    derReader.read("test") { header ->
      assertThat(header.tag).isEqualTo(3L)
      assertThat(derReader.readBitString()).isEqualTo(BitString("0A3B5F291CD0".decodeHex(), 4))
    }

    assertThat(derReader.hasNext()).isFalse()
  }

  @Test fun `encode primitive bit string`() {
    val buffer = Buffer()