how to implement a function that returens an enumeration of objects?

I am working on Design Pattern Project using Java, the class diagram before using the design pattern is provided, since I am new to Java, some of the classes methods description is ambiguous, for example a Class called Mall which has a method Stores(), described as Enumeration Stores(): return an enumeration of the stores in the mall. the class diagram is attached, What is by enumeration return type, please give an example if possible

https://www.dropbox.com/s/kbug0ow3e14284b/DP_Project_1182.pdf?dl=0

public class Mall {
    private String mallId;
    private Store[] Stores;
    private Customer[] customers;

    public void enter(Customer c){}
    public void exit(Customer C){}
    public ShoppingCart getShopingCart()
    {
        return new ShoppingCart();
    }
    public Customer[] customers()
    {

    }
    public Store[] stores()
    {
    }
    void addStore(Store S)
    {

    }


}