Project Description @@@@@@

Here we are two things on top of session 13 assignment (https://github.com/Mutum/Epai_session_13):

1. Refactor the Polygon class so that all the calculated properties are lazy properties, i.e. they should still be calculated properties, but they should not have to get recalculated more than once (since we made our Polygon class "immutable").

2. Refactor the Polygons (sequence) type, into an iterable. Make sure also that the elements in the iterator are computed lazily - i.e. you can no longer use a list as an underlying storage mechanism for your polygons. You'll need to implement both an iterable, and an iterator.

Additional:

Certain testing are done to validate code