Objects
https://docs.google.com/presentation/d/14Gr5TlSXzKsapTqdjUsFFo8a87wZ8WJ6yzyfqLrVfqw/edit?usp=sharing
https://docs.google.com/presentation/d/1lh3SnlzDBPP0tGFIStXZQ-aphNKqzYeR1dQX_HclL4s/edit?usp=sharing