code: function _createRenderable (id, data) {
          var option = this.options.createRenderables[Array.isArray(id) ? id[0] : id];
          if (option instanceof Function) {
              return option.call(this, id, data);
          }
          else if (!option) {
              return undefined;
          }
          if ((data !== undefined) && (data instanceof Object)) {
              return data;
          }
          var surface = new Surface({
              classes: this.classes,
              content: data ? ('<div>' + data + '</div>') : undefined
          });
          if (Array.isArray(id)) {
              for (var i = 0; i < id.length; i++) {
                  surface.addClass(id[i]);
              }
          }
          else {
              surface.addClass(id);
          }
          return surface;
      }
docs: Creates a new renderable for the given renderable-id.