code: function(model, attributes, opt) {
  
          opt || (opt = {});
  
          // update the link path
          this.updateConnection(opt);
  
          // update SVG attributes defined by 'attrs/'.
          this.updateDOMSubtreeAttributes(this.el, this.model.attr(), { selectors: this.selectors });
  
          this.updateDefaultConnectionPath();
  
          // update the label position etc.
          this.updateLabelPositions();
          this.updateToolsPosition();
          this.updateArrowheadMarkers();
  
          this.updateTools(opt);
          // Local perpendicular flag (as opposed to one defined on paper).
          // Could be enabled inside a connector/router. It's valid only
          // during the update execution.
          this.options.perpendicular = null;
          // Mark that postponed update has been already executed.
          this.updatePostponed = false;
  
          return this;
      }
docs: Updating. --------- Default is to process the `attrs` object and set attributes on subelements based on the selectors.