docs: function(node, feature) {
          var name = this.createElementNS(this.namespaces.gpx, 'name');
          name.appendChild(this.createTextNode(
              feature.attributes.name || feature.id));
          node.appendChild(name);
          var desc = this.createElementNS(this.namespaces.gpx, 'desc');
          desc.appendChild(this.createTextNode(
              feature.attributes.description || this.defaultDesc));
          node.appendChild(desc);
          // TBD - deal with remaining (non name/description) attributes.
      }