anchor.diff:    Expect.isTrue(map3exp is Map<double, int>);
   
     var map3 = <double,int>{for (var i = 1; i < 10; i += 5) i + 1.5: i};
  -  // map3exp {2.5: 1, 7.5: 6}
     Expect.isTrue(map3 is Map<double, int>);
  -  Expect.listEquals(map3exp, map3);
  +  Expect.mapEquals(map3exp, map3);
   
     var map4exp = <num, num>{};
     for (var i = 1.1; i < 10; i += 5) {
  
positive.code:   Expect.isTrue(map1exp is Map<int, int>);
  
    var map1 = <int, int>{for (var i = 1; i < 10; i += 3) i: i + 1};
    // map1exp {1: 2, 4: 5, 7: 8}
    Expect.isTrue(map1 is Map<int, int>);
    Expect.mapEquals(map1exp, map1);
  
  
negative.code: 
    var map4 = <num, num>{for (var i = 1.1; i < 10; i += 5) i: i + 2,
        for (var i = 2; i < 6; i++) i: i + 3};
    Expect.isTrue(map4 is Map<num, num>);
    Expect.mapEquals(map4exp, map4);
  
    var map5exp = <int, Function>{};
    for (var i = 1; i < 4; i++) {
      map5exp[i] = () => i + 10;
    }
    var map5 = <int, Function>{for (var i = 1; i < 4; i++) i: () => i + 10};
    Expect.isTrue(map5 is Map<int, Function>);
    Expect.mapEquals(map5exp, map5);
  }
  