this by class binding for root item

static/nb.js

@@ -59,7 +59,7 @@ function nbInit(a,b){
                     callback(item, $s, selector, $s[selector][i], undefined, true);
                 }
                 else {
-                    var res = callback(item, $s, selector);
+                    var res = callback(item, $s, selector, undefined, undefined, true);
                     if (typeof res !== "undefined"){
                         result.push(res)
                     }