anchor.diff: +var familiarityView_rendered = false;
  +
   function familiarityHashForPage(callback) {
       if (typeof(callback) != 'function') {
           callback = function (familiarity_hash) {
  
positive.code:         var _div = $('<div id="familiarity_dim"></div>');
          _div.appendTo(_body);
  
      } else {
          $.each($('.familiarity-bubble-parent'), function (index, element) {
              $(element).removeClass('familiarity-bubble-parent').tooltipster('destroy');
  
negative.code: //        $('.familiarity-bubble-parent').removeClass('familiarity-bubble-parent');
          $('#familiarity_dim').remove();
          $('body').removeClass('familiarity-view');
  
          //Marking flag that familiarity_view is removed from viewport
          familiarityView_rendered = false;
      }
  }
  
  // Show and hide on F1 and ESC key respectively
  $(document).keyup(function (e) {
      console.log("e.keyCode: " + e.keyCode);
      if (e.keyCode == 27 && familiarityView_rendered) { //ESC key pressed
          familiarityView(false);
      }
      if (e.keyCode == 112 && !familiarityView_rendered) { //F1 key pressed
          familiarityView();
      }
  });