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 // Iterator prototype surfaces.

 load(libdir + "asserts.js");

 load(libdir + "iteration.js");

 function test(constructor) {

     var proto = Object.getPrototypeOf(constructor()[std_iterator]());

     var names = Object.getOwnPropertyNames(proto);

     names.sort();

     assertDeepEq(names, [std_iterator, 'next']);

     var desc = Object.getOwnPropertyDescriptor(proto, 'next');

     assertEq(desc.configurable, true);

     assertEq(desc.enumerable, false);

     assertEq(desc.writable, true);

     assertEq(proto[std_iterator](), proto);

     assertIteratorDone(proto, undefined);

 }

 //test(Array);

 test(Map);

 test(Set);