text: // --- INTERNAL USE ONLY ---
  
  /** @description
   * if a test contains an `external` propery as string
   * or as Array of strings, these will be injected in the page
   * before the test will be executed.
   * Handy specially with tests helpers able to deal with the DOM
   * in a simplified way than native API would offer (jQuery or such)
   */
  
  // holds all external libraries so these will be
  // downloaded only once
  var JSContent = {};
  
  // ask the server to download the source of the library
  // throws if the returned status is not in range 200-399
  function downloadJSContent(src) {
    var xhr = XHR();
    xhr.open('GET', '/' + encodeURIComponent('<<<' + src), false);
    xhr.send(null);
    if (!/^(?:2|3)\d{2}$/.test(xhr.status)) {
      throw new Error('unable to downlaod src');
    }
    return xhr.responseText;
  }
  
  // populate an array of urls with relative content per each url
  function grabJSContent(libraries) {
    for(var i = 0, src; i < libraries.length; i++) {
      src = libraries[i];
      libraries[i] = JSContent[src] || (
        JSContent[src] = downloadJSContent(src)
      );
    }
    return libraries;
  }