Three Promises, Many Classes

Five things this topic established, and where each one was.

What the topic established, and which card it was on
The thing	Where
`List` keeps order and duplicates, `Set` keeps each once, `Queue` decides what is next	Three Interfaces, and the One Promise Each Makes
`contains` is a walk on a list and a lookup on a set	List, Set and Queue on Order, Duplicates and Access
Name the interface everywhere except after `new`	Declare the Interface, Create the Implementation
`Map` holds pairs, so it sits outside `Collection` and offers three views instead	Why Map Is Not a Collection
`List.of` is unmodifiable, and `add` throws rather than failing to compile	Why List.of(...) Refuses add()

The one worth carrying: choose the interface from the promise you need, and choose the class afterwards. Every topic after this one is about the second half of that sentence.

Java
Java Collections