code: function() {
      var roots = [];
      
      for (var i=0; i < this.nodes.length; i++) {
        var node = this.nodes[i];
        
        if (node.parent == undefined) roots.push(node);
      };
      
      return roots;
    }
docs: Returns all top-level (root) nodes in this template tree.
  Templates are tree structures, but there is no guarantee that there is a
  single root node (e.g. a single DOM element that all other elements nest within)
  @return {Array} The array of root nodes