--- /dev/null
+var isObject = require('../internals/is-object');
+var setPrototypeOf = require('../internals/object-set-prototype-of');
+
+// makes subclassing work correct for wrapped built-ins
+module.exports = function ($this, dummy, Wrapper) {
+ var NewTarget, NewTargetPrototype;
+ if (
+ // it can work only with native `setPrototypeOf`
+ setPrototypeOf &&
+ // we haven't completely correct pre-ES6 way for getting `new.target`, so use this
+ typeof (NewTarget = dummy.constructor) == 'function' &&
+ NewTarget !== Wrapper &&
+ isObject(NewTargetPrototype = NewTarget.prototype) &&
+ NewTargetPrototype !== Wrapper.prototype
+ ) setPrototypeOf($this, NewTargetPrototype);
+ return $this;
+};