diff --git a/src/main/resources/core/ployfill.js b/src/main/resources/core/ployfill.js
index 17e4d35..de4c630 100644
--- a/src/main/resources/core/ployfill.js
+++ b/src/main/resources/core/ployfill.js
@@ -1,17 +1,21 @@
 (function(root, logger) {
+    // Init Global Value
     global.root = root;
     global.logger = logger;
+    // Init Global Function
     global.noop = global.engineDisable = function() { };
-    // disable 
     global.engineLoad = load;
     global.load = function __PreventGlobalLoadFunction__() {
         throw new Error('Internal engine system not allow use `load` function!');
     };
+    // Init console and require
     global.console = engineLoad(global.root + '/core/console.js')(logger);
     global.require = engineLoad(global.root + '/core/require.js')(root);
-    String.prototype.contains = function(searchString/*, position*/) {
-        return String.prototype.indexOf.call(this, searchString, arguments[1]) > -1;
+    // String contains playfill
+    String.prototype.contains = function(searchString, position) {
+        return String.prototype.indexOf.call(this, searchString, position) > -1;
     };
+    // ES6 Map Symbol playfill
     require('es6-map/implement');
     require('es6-symbol/implement');
 });