Configring node js.

node_modules/core-js/modules/_wks-define.js

@@ -0,0 +1,9 @@
+var global         = require('./_global')
+  , core           = require('./_core')
+  , LIBRARY        = require('./_library')
+  , wksExt         = require('./_wks-ext')
+  , defineProperty = require('./_object-dp').f;
+module.exports = function(name){
+  var $Symbol = core.Symbol || (core.Symbol = LIBRARY ? {} : global.Symbol || {});
+  if(name.charAt(0) != '_' && !(name in $Symbol))defineProperty($Symbol, name, {value: wksExt.f(name)});
+};