npm and error messages

node_modules/es5-ext/object/is-plain-object.js

@@ -0,0 +1,20 @@
+"use strict";
+
+var getPrototypeOf = Object.getPrototypeOf
+  , prototype = Object.prototype
+  , objToString = prototype.toString
+  , id = Object().toString();
+
+module.exports = function (value) {
+	var proto, valueConstructor;
+	if (!value || typeof value !== "object" || objToString.call(value) !== id) {
+		return false;
+	}
+	proto = getPrototypeOf(value);
+	if (proto === null) {
+		valueConstructor = value.constructor;
+		if (typeof valueConstructor !== "function") return true;
+		return valueConstructor.prototype !== value;
+	}
+	return proto === prototype || getPrototypeOf(proto) === null;
+};