--- /dev/null
+'use strict';
+
+module.exports = function () {
+ var arr = [1, 'foo'], iterator, result;
+ if (typeof arr.keys !== 'function') return false;
+ iterator = arr.keys();
+ if (!iterator) return false;
+ if (typeof iterator.next !== 'function') return false;
+ result = iterator.next();
+ if (!result) return false;
+ if (result.value !== 0) return false;
+ if (result.done !== false) return false;
+ return true;
+};