[PHP] Wyciągnięcie zmiennej z obiektu Opcje

[-Omnik-]

Cześć,
jak wyciągnąć zmienną category_id o wartości 9 z tego obiektu?:

Kod

xmlrpcval Object
(
    [me] => Array
        (
            [array] => Array
                (
                    [0] => xmlrpcval Object
                        (
                            [me] => Array
                                (
                                    [struct] => Array
                                        (
                                            [category_id] => xmlrpcval Object
                                                (
                                                    [me] => Array
                                                        (
                                                            [string] => 9
                                                        )

                                                    [mytype] => 1
                                                    [_php_class] =>
                                                )

                                            [category_name] => xmlrpcval Object
                                                (
                                                    [me] => Array
                                                        (
                                                            [string] => Newsy
                                                        )

                                                    [mytype] => 1
                                                    [_php_class] =>
                                                )

                                        )

                                )

                            [mytype] => 3
                            [_php_class] =>
                        )

                )

        )

    [mytype] => 2
    [_php_class] =>
)