diffKeys static method
Returns all entries of this map according to keys.
which is not in second map.
Example:
diffKeys(map, map2)
Implementation
static Map<dynamic, dynamic> diffKeys(
Map<dynamic, dynamic> map1, Map<dynamic, dynamic> map2) {
map1.removeWhere((dynamic key, dynamic value) => map2.containsKey(key));
return map1;
}