code: function (subject, myDocument) {
      var div = myDocument.createElement('div')
      var kb = UI.store
  
      //  @@ When we can, use CSP to turn off scripts within the iframe
      div.setAttribute('class', 'docView')
      var iframe = myDocument.createElement('IFRAME')
      iframe.setAttribute('src', subject.uri) // allow-same-origin
      iframe.setAttribute('class', 'doc')
  
      var cts = kb.fetcher.getHeader(subject.doc(), 'content-type')
      var ct = cts ? cts[0] : null
      if (ct) {
        console.log('dokieliPane: c-t:' + ct)
      } else {
        console.log('dokieliPane: unknown content-type?')
      }
  
      // @@ NOte beflow - if we set ANY sandbox, then Chrome and Safari won't display it if it is PDF.
      // https://developer.mozilla.org/en-US/docs/Web/HTML/Element/iframe
      // You can;'t have any sandbox and allow plugins.
      // We could sandbox only HTML files I suppose.
      // HTML5 bug: https://lists.w3.org/Archives/Public/public-html/2011Jun/0330.html
  
      // iframe.setAttribute('sandbox', 'allow-same-origin allow-forms'); // allow-scripts ?? no documents should be static
  
      iframe.setAttribute('style', 'resize = both; height: 40em; width:40em;') // @@ improve guess
      //        iframe.setAttribute('height', '480')
      //        iframe.setAttribute('width', '640')
      var tr = myDocument.createElement('tr')
      tr.appendChild(iframe)
      div.appendChild(tr)
      return div
    }
docs: Derived from: humanReadablePane .. share code?