Izmjenjena struktura, dodan backand

web/node_modules/core-js/modules/es6.reflect.prevent-extensions.js

@@ -0,0 +1,16 @@
+// 26.1.12 Reflect.preventExtensions(target)
+var $export            = require('./$.export')
+  , anObject           = require('./$.an-object')
+  , $preventExtensions = Object.preventExtensions;
+
+$export($export.S, 'Reflect', {
+  preventExtensions: function preventExtensions(target){
+    anObject(target);
+    try {
+      if($preventExtensions)$preventExtensions(target);
+      return true;
+    } catch(e){
+      return false;
+    }
+  }
+});