So siehts ganz gut aus !

node_modules/es5-ext/object/validate-stringifiable-value.js

@@ -0,0 +1,8 @@
+"use strict";
+
+var ensureValue   = require("./valid-value")
+  , stringifiable = require("./validate-stringifiable");
+
+module.exports = function (value) {
+	return stringifiable(ensureValue(value));
+};