michael@0: // for-of can be used to iterate over a Map twice.
michael@0: 
michael@0: var map = Map([['a', 0], ['b', 1], ['c', 2]]);
michael@0: var log = '';
michael@0: 
michael@0: for (let i = 0; i < 2; i++) {
michael@0:     for (let [k, v] of map)
michael@0:         log += k + v;
michael@0:     log += ';'
michael@0: }
michael@0: assertEq(log, 'a0b1c2;a0b1c2;');