anchor.diff:      return s;
     }
   
  -  void gotoStep(int step) {
  +  void goto(int step) {
       // Iterate over attributes of the step jumped to and apply CSS
       mSteps[step].attributes.forEach((k,v) {
         ;
  
positive.code:     // force going to active step again, to trigger rescaling
      pres.goto(document.query('.active'), 500);
    }, 250));
  }
  
negative.code: 
    // trigger impress action (next or prev) on keyup
    document.on.keyUp.add((event) {
      switch (event.keyCode) {
        case 33: // pg up
          pres.prev();
          break;
        case 37: // left
          pres.prev();
          break;
        case 38: // up
          pres.prev();
          break;
        case 9:  // tab
          pres.next();
          break;
        case 32: // space
          pres.next();
          break;
        case 34: // pg down
          pres.next();
          break;
        case 39: // right
          pres.next();
          break;
        case 40: // down
          pres.next();
          break;
      }
      event.preventDefault();
    });
  
    /* not used atm
  
    // delegated handler for clicking on the links to presentation steps
    document.on.click.add((event) {
  