--- /dev/null
+'use strict';
+
+var create = Object.create, getPrototypeOf = Object.getPrototypeOf
+ , x = {};
+
+module.exports = function (/*customCreate*/) {
+ var setPrototypeOf = Object.setPrototypeOf
+ , customCreate = arguments[0] || create;
+ if (typeof setPrototypeOf !== 'function') return false;
+ return getPrototypeOf(setPrototypeOf(customCreate(null), x)) === x;
+};