npm and error messages

node_modules/es5-ext/object/primitive-set.js

@@ -0,0 +1,12 @@
+"use strict";
+
+var forEach = Array.prototype.forEach, create = Object.create;
+
+// eslint-disable-next-line no-unused-vars
+module.exports = function (arg /*, …args*/) {
+	var set = create(null);
+	forEach.call(arguments, function (name) {
+		set[name] = true;
+	});
+	return set;
+};