So siehts ganz gut aus !

node_modules/es5-ext/test/object/ensure-plain-object.js

@@ -0,0 +1,16 @@
+"use strict";
+
+module.exports = function (t, a) {
+	// Just sanity checks, as logic is tested at isPlainFunction
+	var obj = {};
+	a(t(obj), obj, "Reguar object instance");
+	obj = Object.create(null);
+	a(t(obj), obj, "Null prototype");
+	a.throws(
+		function () {
+			t(function () {});
+		},
+		TypeError,
+		"Error"
+	);
+};