michael@0: load(libdir + "asserts.js");
michael@0: 
michael@0: var g = newGlobal();
michael@0: for (var cls of [Map, Set]) {
michael@0:     var getter = Object.getOwnPropertyDescriptor(cls.prototype, "size").get;
michael@0:     assertThrowsInstanceOf(function () { getter.apply(g, []); }, g.TypeError);
michael@0: }