How to define/design a java class

I have two classes Class1 and Class2:

inside a Class1 class, one of the method is written like this below:

public class Class1 {

    public List<Class2> getMembers() {

        List<IpAddress> addresses = new ArrayList<IpAddress>();
           ...
           ...
       return addresses
    }

    // other functions

}

I want to write/design Class2 class so, that above function is valid.

public class Class2 {

}

can anyone please help me.

-Thanks