private List <Tuple <Street, uint[][]> > getRandomizedBuildingsOrders()
{
List <Tuple <Street, uint[][]> > buildingList = this.street2Buildings.
ToList().SelectMany(pair => {
Street street = pair.Key;
return(pair.Value.Select(buildingCoordinates =>
new Tuple <Street, uint[][]> (street, buildingCoordinates)
));
}).ToList();
return(buildingList.Select(pair => new { value = pair,
rand = random.ContinuousUniform(0, 1) }).OrderBy(pair => pair.rand).
Select(pair => pair.value).ToList());
}