--- /dev/null
+var wellKnownSymbol = require('../internals/well-known-symbol');
+var Iterators = require('../internals/iterators');
+
+var ITERATOR = wellKnownSymbol('iterator');
+var ArrayPrototype = Array.prototype;
+
+// check on default Array iterator
+module.exports = function (it) {
+ return it !== undefined && (Iterators.Array === it || ArrayPrototype[ITERATOR] === it);
+};