firstClassCollection1.java

// Creata a hash map class and put values into the map
Map<String, String> map = new HashMap<>();
map.put("1", "A");
map.put("2", "B");
map.put("3", "C");


// Create a class that only contains a collection.
public class GameRanking {

    private Map<String, String> ranks;

    public GameRanking(Map<String, String> ranks) {
        this.ranks = ranks;
    }
}