// A Set iterator does not iterate over new entries added after it throws StopIteration. load(libdir + "iteration.js"); var set = new Set(); var iter0 = set[Symbol.iterator](), iter1 = set[Symbol.iterator](); assertIteratorDone(iter0, undefined); // closes iter0 set.add("x"); assertIteratorDone(iter0, undefined); // already closed assertIteratorNext(iter1, "x"); // was not yet closed