old_contents: // Apply Node polyfills as necessary.
  var window = {
    Date: Date,
    addEventListener: function() {},
    removeEventListener: function() {}
  };
  
  var location = {
    href: "",
    host: "",
    hostname: "",
    protocol: "",
    origin: "",
    port: "",
    pathname: "",
    search: "",
    hash: "",
    username: "",
    password: ""
  };
  var document = { body: {}, createTextNode: function() {}, location: location };
  
  if (typeof XMLHttpRequest === "undefined") {
    XMLHttpRequest = function() {
      return {
        addEventListener: function() {},
        open: function() {},
        send: function() {}
      };
    };
  
    var oldConsoleWarn = console.warn
    console.warn = function () {
      if (arguments.length === 1 && arguments[0].indexOf('Compiled in DEV mode') === 0) return
      return oldConsoleWarn.apply(console, arguments)
    }
  }
  
  if (typeof FormData === "undefined") {
    FormData = function() {
      this._data = [];
    };
    FormData.prototype.append = function() {
      this._data.push(Array.prototype.slice.call(arguments));
    };
  }
  
new_contents: // Apply Node polyfills as necessary.
  var window = {
    Date: Date,
    addEventListener: function() {},
    removeEventListener: function() {}
  };
  
  var location = {
    href: "",
    host: "",
    hostname: "",
    protocol: "",
    origin: "",
    port: "",
    pathname: "",
    search: "",
    hash: "",
    username: "",
    password: ""
  };
  var document = { body: {}, createTextNode: function() {}, location: location };
  
  if (typeof FileList === "undefined") {
      FileList = function() {};
  }
  
  if (typeof XMLHttpRequest === "undefined") {
    XMLHttpRequest = function() {
      return {
        addEventListener: function() {},
        open: function() {},
        send: function() {}
      };
    };
  
    var oldConsoleWarn = console.warn
    console.warn = function () {
      if (arguments.length === 1 && arguments[0].indexOf('Compiled in DEV mode') === 0) return
      return oldConsoleWarn.apply(console, arguments)
    }
  }
  
  if (typeof FormData === "undefined") {
    FormData = function() {
      this._data = [];
    };
    FormData.prototype.append = function() {
      this._data.push(Array.prototype.slice.call(arguments));
    };
  }
  
subject: Add FileList to polyfills