GENERICS

class Box<T> {
    private T item;
    
    public void set(T item) { this.item = item; }
    public T get() { return this.item; }
}

public class Main {
    public static void main(String[] args) {
        Box<String> stringBox = new Box<>();
        stringBox.set("Hello Generics");
        System.out.println(stringBox.get());
        
        Box<Integer> intBox = new Box<>();
        intBox.set(123);
        System.out.println(intBox.get() * 2);
    }
}