Configring node js.

node_modules/core-js/modules/_flags.js

@@ -0,0 +1,13 @@
+'use strict';
+// 21.2.5.3 get RegExp.prototype.flags
+var anObject = require('./_an-object');
+module.exports = function(){
+  var that   = anObject(this)
+    , result = '';
+  if(that.global)     result += 'g';
+  if(that.ignoreCase) result += 'i';
+  if(that.multiline)  result += 'm';
+  if(that.unicode)    result += 'u';
+  if(that.sticky)     result += 'y';
+  return result;
+};