<!DOCTYPE html>
<html>
  <head>
    <title>Post and dump binary data</title>
  </head>
  <body>
    <script type='text/javascript'>
      var xhr = new XMLHttpRequest()
      var url = 'http://localhost:3500/binary'
      xhr.onload = function() {
        var arrayBuffer = xhr.response
        var uint8 = new Uint8Array(arrayBuffer)
        var divNode = document.getElementById('result')
        divNode.innerText = uint8.join(', ')
      }
      xhr.open('POST', url + '?_=' + Date.now(), true)
      xhr.set