code: function(id, name, index) {
      if(!this.config.selectOnHover) return;
      var s = this.selected;
      if(s.id != id || s.name != name 
          || s.index != index) {
        s.id = id;
        s.name = name;
        s.index = index;
        this.st.graph.eachNode(function(n) {
          n.setData('border', false);
        });
        if(id) {
          var n = this.st.graph.getNode(id);
          n.setData('border', s);
          var link = index === 0? 'prev':'next';
          link = n.getData(link);
          if(link) {
            n = this.st.graph.getByName(link);
            if(n) {
              n.setData('border', {
                name: name,
                index: 1-index
              });
            }
          }
        }
        this.st.plot();
      }
    }
docs: adds the little brown bar when hovering the node