Inner render function of the Group
function _innerRender() {
        var specs = this._specs;
        for (var i3 = 0, j3 = specs.length; i3 < j3; i3++) {
            if (specs[i3].renderNode) {
                specs[i3].target = specs[i3].renderNode.render();
            }
        }

        // Add our cleanup-registration id also to the list, so that the
        // cleanup function is called by famo.us when the LayoutController is
        // removed from the render-tree.
        if (!specs.length || (specs[specs.length-1] !== this._cleanupRegistration)) {
            specs.push(this._cleanupRegistration);
        }
        return specs;
    }