st _drawFail = () => {
    console.log('reality tab load error: ' + u);
  };

  const iframe = document.createElement('iframe');
  iframe.onconsole = (jsString, scriptUrl, startLine) => {
    console.log('parent got console', {jsString, scriptUrl, startLine});
  };
  iframe.onload = function() {
    const contentDocument = (() => {
      try {
        if (this.contentDocument) { // this potentially throws
          return this.contentDocument;
        } else {
          return null;
        }
      } catch(