Izmjenjena struktura, dodan backand

web/node_modules/core-js/modules/es6.object.keys.js

@@ -0,0 +1,8 @@
+// 19.1.2.14 Object.keys(O)
+var toObject = require('./$.to-object');
+
+require('./$.object-sap')('keys', function($keys){
+  return function keys(it){
+    return $keys(toObject(it));
+  };
+});