abstract public class AnInterfacePOA implements AnInterfaceOperations {
    public AnInterface _this () { ... }
    ...
}

public class AnInterfacePOATie extends AnInterfacePOA {
    private AnInterfaceOperations _delegate;

    public AnInterfacePOATie (AnInterfaceOperations delegate)
    { _delegate = delegate; }

    public AnInterfaceOperations _delegate ()
    { return (_delegate); }

    public void _delegate (AnInterfaceOperations delegate)
    { _delegate = delegate; }

    public ... AnOperation (...) { return (_delegate.AnOperation (...); }
}