+var global = require('../internals/global');
+var call = require('../internals/function-call');
+var aCallable = require('../internals/a-callable');
var anObject = require('../internals/an-object');
+var tryToString = require('../internals/try-to-string');
var getIteratorMethod = require('../internals/get-iterator-method');
-module.exports = function (it) {
- var iteratorMethod = getIteratorMethod(it);
- if (typeof iteratorMethod != 'function') {
- throw TypeError(String(it) + ' is not iterable');
- } return anObject(iteratorMethod.call(it));
+var TypeError = global.TypeError;
+
+module.exports = function (argument, usingIterator) {
+ var iteratorMethod = arguments.length < 2 ? getIteratorMethod(argument) : usingIterator;
+ if (aCallable(iteratorMethod)) return anObject(call(iteratorMethod, argument));
+ throw TypeError(tryToString(argument) + ' is not iterable');
};