Configring node js.

node_modules/core-js/library/modules/es6.map.js

@@ -0,0 +1,17 @@
+'use strict';
+var strong = require('./_collection-strong');
+
+// 23.1 Map Objects
+module.exports = require('./_collection')('Map', function(get){
+  return function Map(){ return get(this, arguments.length > 0 ? arguments[0] : undefined); };
+}, {
+  // 23.1.3.6 Map.prototype.get(key)
+  get: function get(key){
+    var entry = strong.getEntry(this, key);
+    return entry && entry.v;
+  },
+  // 23.1.3.9 Map.prototype.set(key, value)
+  set: function set(key, value){
+    return strong.def(this, key === 0 ? 0 : key, value);
+  }
+}, strong, true);