code: function() {
  
      if (!this._containsCover()) return;
  
      var self = this;
      var $cover = this.$(".cover");
      var $img = $cover.find("img");
      var $shadow = this.$(".shadow");
      var url = this._getCoverURL();
  
      if (!this._isValidURL(url)) {
        $img.hide();
        $shadow.hide();
        cdb.log.info("Header image url not valid");
        return;
      }
  
      // configure spinner
      var target  = document.getElementById('spinner');
      var opts    = { lines: 9, length: 4, width: 2, radius: 4, corners: 1, rotate: 0, color: '#ccc', speed: 1, trail: 60, shadow: true, hwaccel: false, zIndex: 2e9 };
      var spinner = new Spinner(opts).spin(target);
  
      // create the image
  
      $img.hide(function() {
        this.remove();
      });
  
      $img = $("<img />").attr("src", url);
      $cover.append($img);
  
      $img.load(function(){
        spinner.stop();
  
        var w  = $img.width();
        var h  = $img.height();
        var coverWidth = $cover.width();
        var coverHeight = $cover.height();
  
        var ratio = h / w;
        var coverRatio = coverHeight / coverWidth;
  
        // Resize rules
        if ( w > coverWidth && h > coverHeight) { // bigger image
          if ( ratio < coverRatio ) $img.css({ height: coverHeight });
          else {
            var calculatedHeight = h / (w / coverWidth);
            $img.css({ width: coverWidth, top: "50%", position: "absolute", "margin-top": -1*parseInt(calculatedHeight, 10)/2 });
          }
        } else {
          var calculatedHeight = h / (w / coverWidth);
          $img.css({ width: coverWidth, top: "50%", position: "absolute", "margin-top": -1*parseInt(calculatedHeight, 10)/2 });
        }
  
        $img.fadeIn(300);
      })
      .error(function(){
        spinner.stop();
      });
    }
docs: Attempts to load the cover URL and show it