override fun write(
      source: Buffer,
      byteCount: Long,
    ) {
      check(!closed) { "closed" }
      if (byteCount == 0L) return

      with(socket.sink) {
        writeHexadecimalUnsignedLong(byteCount)
        writeUtf8("\r\n")
        write(source, byteCount)
        writeUtf8("\r\n")
      }
    }

    @Synchronized
    override fun flush() {

      if (i == 16) result.writeByte(':'.code)
    } else {
      if (i > 0) result.writeByte(':'.code)
      val group = address[i] and 0xff shl 8 or (address[i + 1] and 0xff)
      result.writeHexadecimalUnsignedLong(group.toLong())
      i += 2
    }
  }
  return result.readUtf8()
}

/**
 * Returns the canonical address for [address]. If [address] is an IPv6 address that is mapped to an