michael@0: // Nested for-of loops can iterate over a Map.
michael@0: 
michael@0: var map = Map([['a', 0], ['b', 1]]);
michael@0: var log = '';
michael@0: for (let [k0, v0] of map) {
michael@0:     log += k0 + v0 + ':'
michael@0:     for (let [k1, v1] of map)
michael@0:         log += k1 + v1;
michael@0:     log += ';'
michael@0: };
michael@0: assertEq(log, 'a0:a0b1;b1:a0b1;');