Task: Need to implement a collection that has a fixed size. Size is set:
- the default is 16
- according to the user's instructions.
The size of the collection after the initialization can not change. Each new element is added to the end. After the number of elements has reached the maximum - when adding a new element, the collection "shifts" to the left. The 1st element is deleted, and each next moves to one element to the left.