How to use the billiard.util.Finalize function in billiard

def __init__(self, app=None, hostname=None, **kwargs):
        self.app = app or self.app
        self.hostname = default_nodename(hostname)
        self.app.loader.init_worker()
        self.on_before_init(**kwargs)
        self.setup_defaults(**kwargs)
        self.on_after_init(**kwargs)

        self.setup_instance(**self.prepare_args(**kwargs))
        self._finalize = [
            Finalize(self, self._send_worker_shutdown, exitpriority=10),
        ]

# while waiting for unfinished work at shutdown.
            if not threads:
                self.check_timeouts = self._timeout_handler.handle_event
        else:
            self._timeout_handler = None
            self._timeout_handler_started = False
            self._timeout_handler_mutex = None

        # Thread processing results in the outqueue.
        self._result_handler = self.create_result_handler()
        self.handle_result_event = self._result_handler.handle_event

        if threads:
            self._result_handler.start()

        self._terminate = Finalize(
            self, self._terminate_pool,
            args=(self._taskqueue, self._inqueue, self._outqueue,
                  self._pool, self._worker_handler, self._task_handler,
                  self._result_handler, self._cache,
                  self._timeout_handler,
                  self._help_stuff_finish_args()),
            exitpriority=15,
        )

# On process exit we will wait for data to be flushed to pipe.
        #
        # However, if this process created the queue then all
        # processes which use the queue will be descendants of this
        # process.  Therefore waiting for the queue to be flushed
        # is pointless once all the child processes have been joined.
        created_by_this_process = (self._opid == os.getpid())
        if not self._joincancelled and not created_by_this_process:
            self._jointhread = Finalize(
                self._thread, Queue._finalize_join,
                [weakref.ref(self._thread)],
                exitpriority=-5
            )

        # Send sentinel to the thread queue object when garbage collected
        self._close = Finalize(
            self, Queue._finalize_close,
            [self._buffer, self._notempty],
            exitpriority=10
        )

# send information to child
                prep_data = get_preparation_data(process_obj._name)
                os.close(from_parent_fd)
                to_child = os.fdopen(to_child_fd, 'wb')
                Popen._tls.process_handle = self.pid
                try:
                    dump(prep_data, to_child, HIGHEST_PROTOCOL)
                    dump(process_obj, to_child, HIGHEST_PROTOCOL)
                finally:
                    del(Popen._tls.process_handle)
                    to_child.close()

            # `w` will be closed when the child exits, at which point `r`
            # will become ready for reading (using e.g. select()).
            os.close(w)
            util.Finalize(self, os.close, (r,))

def __init__(self, address, backlog=None):
            self._address = address
            self._handle_queue = [self._new_handle(first=True)]

            self._last_accepted = None
            sub_debug('listener created with address=%r', self._address)
            self.close = Finalize(
                self, PipeListener._finalize_pipe_listener,
                args=(self._handle_queue, self._address), exitpriority=0
            )

# SO_REUSEADDR has different semantics on Windows (issue #2550).
            if os.name == 'posix':
                self._socket.setsockopt(socket.SOL_SOCKET,
                                        socket.SO_REUSEADDR, 1)
            self._socket.setblocking(True)
            self._socket.bind(address)
            self._socket.listen(backlog)
            self._address = self._socket.getsockname()
        except OSError:
            self._socket.close()
            raise
        self._family = family
        self._last_accepted = None

        if family == 'AF_UNIX':
            self._unlink = util.Finalize(
                self, os.unlink, args=(address,), exitpriority=0
            )
        else:
            self._unlink = None

try:
            # SO_REUSEADDR has different semantics on Windows (Issue #2550).
            if os.name == 'posix':
                self._socket.setsockopt(socket.SOL_SOCKET,
                                        socket.SO_REUSEADDR, 1)
            self._socket.bind(address)
            self._socket.listen(backlog)
            self._address = self._socket.getsockname()
        except OSError:
            self._socket.close()
            raise
        self._family = family
        self._last_accepted = None

        if family == 'AF_UNIX':
            self._unlink = Finalize(
                self, os.unlink, args=(address,), exitpriority=0
            )
        else:
            self._unlink = None

)
        self._thread.daemon = True

        debug('doing self._thread.start()')
        self._thread.start()
        debug('... done self._thread.start()')

        # On process exit we will wait for data to be flushed to pipe.
        #
        # However, if this process created the queue then all
        # processes which use the queue will be descendants of this
        # process.  Therefore waiting for the queue to be flushed
        # is pointless once all the child processes have been joined.
        created_by_this_process = (self._opid == os.getpid())
        if not self._joincancelled and not created_by_this_process:
            self._jointhread = Finalize(
                self._thread, Queue._finalize_join,
                [weakref.ref(self._thread)],
                exitpriority=-5
            )

        # Send sentinel to the thread queue object when garbage collected
        self._close = Finalize(
            self, Queue._finalize_close,
            [self._buffer, self._notempty],
            exitpriority=10
        )

# send information to child
                prep_data = get_preparation_data(process_obj._name)
                os.close(from_parent_fd)
                to_child = os.fdopen(to_child_fd, 'wb')
                Popen._tls.process_handle = self.pid
                try:
                    dump(prep_data, to_child, HIGHEST_PROTOCOL)
                    dump(process_obj, to_child, HIGHEST_PROTOCOL)
                finally:
                    del(Popen._tls.process_handle)
                    to_child.close()

            # `w` will be closed when the child exits, at which point `r`
            # will become ready for reading (using e.g. select()).
            os.close(w)
            util.Finalize(self, os.close, (r,))