docs: function(canvas, node, controller) {
        var id = node.id, tag = this.getLabel(id);
  
        if(!tag && !(tag = document.getElementById(id))) {
          tag = document.createElement('div');
          var container = this.getLabelContainer();
          tag.id = id;
          tag.className = 'node';
          tag.style.position = 'absolute';
          controller.onCreateLabel(tag, node);
          container.appendChild(tag);
          this.labels[node.id] = tag;
        }
  
        this.placeLabel(tag, node, controller);
      }