StreetGroups are implemented. In BoardSpecification.txt file, color type of streetTiles are defined in their policies intially which will be deleted while after parsing policies to policies ArrayList of PropertyDeed of related StreetTile.

StreetGroup has an factory method which is called addNewStreetToGroup() to add a new street to an existing StreetGroup, if there is no such a created StreetGroup, it will first create it then add that street to that StreetGroup