Configring node js.

node_modules/core-js/modules/_meta.js

@@ -0,0 +1,53 @@
+var META     = require('./_uid')('meta')
+  , isObject = require('./_is-object')
+  , has      = require('./_has')
+  , setDesc  = require('./_object-dp').f
+  , id       = 0;
+var isExtensible = Object.isExtensible || function(){
+  return true;
+};
+var FREEZE = !require('./_fails')(function(){
+  return isExtensible(Object.preventExtensions({}));
+});
+var setMeta = function(it){
+  setDesc(it, META, {value: {
+    i: 'O' + ++id, // object ID
+    w: {}          // weak collections IDs
+  }});
+};
+var fastKey = function(it, create){
+  // return primitive with prefix
+  if(!isObject(it))return typeof it == 'symbol' ? it : (typeof it == 'string' ? 'S' : 'P') + it;
+  if(!has(it, META)){
+    // can't set metadata to uncaught frozen object
+    if(!isExtensible(it))return 'F';
+    // not necessary to add metadata
+    if(!create)return 'E';
+    // add missing metadata
+    setMeta(it);
+  // return object ID
+  } return it[META].i;
+};
+var getWeak = function(it, create){
+  if(!has(it, META)){
+    // can't set metadata to uncaught frozen object
+    if(!isExtensible(it))return true;
+    // not necessary to add metadata
+    if(!create)return false;
+    // add missing metadata
+    setMeta(it);
+  // return hash weak collections IDs
+  } return it[META].w;
+};
+// add metadata on freeze-family methods calling
+var onFreeze = function(it){
+  if(FREEZE && meta.NEED && isExtensible(it) && !has(it, META))setMeta(it);
+  return it;
+};
+var meta = module.exports = {
+  KEY:      META,
+  NEED:     false,
+  fastKey:  fastKey,
+  getWeak:  getWeak,
+  onFreeze: onFreeze
+};