Configring node js.

node_modules/core-js/modules/_metadata.js

@@ -0,0 +1,51 @@
+var Map     = require('./es6.map')
+  , $export = require('./_export')
+  , shared  = require('./_shared')('metadata')
+  , store   = shared.store || (shared.store = new (require('./es6.weak-map')));
+
+var getOrCreateMetadataMap = function(target, targetKey, create){
+  var targetMetadata = store.get(target);
+  if(!targetMetadata){
+    if(!create)return undefined;
+    store.set(target, targetMetadata = new Map);
+  }
+  var keyMetadata = targetMetadata.get(targetKey);
+  if(!keyMetadata){
+    if(!create)return undefined;
+    targetMetadata.set(targetKey, keyMetadata = new Map);
+  } return keyMetadata;
+};
+var ordinaryHasOwnMetadata = function(MetadataKey, O, P){
+  var metadataMap = getOrCreateMetadataMap(O, P, false);
+  return metadataMap === undefined ? false : metadataMap.has(MetadataKey);
+};
+var ordinaryGetOwnMetadata = function(MetadataKey, O, P){
+  var metadataMap = getOrCreateMetadataMap(O, P, false);
+  return metadataMap === undefined ? undefined : metadataMap.get(MetadataKey);
+};
+var ordinaryDefineOwnMetadata = function(MetadataKey, MetadataValue, O, P){
+  getOrCreateMetadataMap(O, P, true).set(MetadataKey, MetadataValue);
+};
+var ordinaryOwnMetadataKeys = function(target, targetKey){
+  var metadataMap = getOrCreateMetadataMap(target, targetKey, false)
+    , keys        = [];
+  if(metadataMap)metadataMap.forEach(function(_, key){ keys.push(key); });
+  return keys;
+};
+var toMetaKey = function(it){
+  return it === undefined || typeof it == 'symbol' ? it : String(it);
+};
+var exp = function(O){
+  $export($export.S, 'Reflect', O);
+};
+
+module.exports = {
+  store: store,
+  map: getOrCreateMetadataMap,
+  has: ordinaryHasOwnMetadata,
+  get: ordinaryGetOwnMetadata,
+  set: ordinaryDefineOwnMetadata,
+  keys: ordinaryOwnMetadataKeys,
+  key: toMetaKey,
+  exp: exp
+};