public class Address
{
    public Address ()
    {
        
    }

    public String identifier ()
    {

    }

    private String _id;
}
@@ -24,115 +24,235 @@
     
-public Address ()%0A    %7B%0A        %0A    %7D%0A%0A    public String identifier ()%0A    %7B%0A%0A    %7D%0A%0A    private String _id;
+// return the next unique address%0A    %0A    public static synchronized final int getNextAddress ()%0A    %7B%0A        _address++;%0A%0A        return _address;%0A    %7D%0A%0A    public static int _address = -1;%0A%0A    private Address ()%0A    %7B%0A    %7D
 %0A%7D

Update Address.java