npm and error messages

node_modules/es6-map/is-native-implemented.js

@@ -0,0 +1,9 @@
+// Exports true if environment provides native `Map` implementation,
+// whatever that is.
+
+'use strict';
+
+module.exports = (function () {
+	if (typeof Map === 'undefined') return false;
+	return (Object.prototype.toString.call(new Map()) === '[object Map]');
+}());