How to use the udiskie.async_.Coroutine.from_generator_function function in udiskie

    @Coroutine.from_generator_function
    def update(self, object_path):
        device = yield self._get_updated_device(object_path)
        if device is not None:
            self._devices[object_path] = device
        yield Return(device)

    @Coroutine.from_generator_function
    def get_property_interface(self, interface_name=None):
        proxy = yield self._get_interface(PropertiesProxy.Interface)
        yield Return(PropertiesProxy(proxy, interface_name))

    @Coroutine.from_generator_function
    def call(self, interface_name, method_name, signature='()', *args):
        proxy = yield self.get_interface(interface_name)
        result = yield proxy.call(method_name, signature, *args)
        yield Return(result)

    @Coroutine.from_generator_function
    def _get_updated_device(self, object_path):
        obj = self._proxy.object.bus.get_object(object_path)
        try:
            prop_prox = self._property_proxy[object_path]
        except KeyError:
            prop_prox = yield obj.get_property_interface(Device.Interface)
            self._property_proxy[object_path] = prop_prox

        try:
            properties = yield prop_prox.GetAll()
        except GLib.GError:
            self._invalidate(object_path)
            yield Return(None)
            # TODO: return something useful? (NullDevice)
        else:
            itfc_prox = MethodsProxy(obj, Device.Interface)

    @Coroutine.from_generator_function
    def get_version(cls):
        service = (cls.BusName, cls.ObjectPath,
                   'org.freedesktop.DBus.Properties')
        manager = yield connect_service(*service)
        version = yield DBusCall(manager._proxy, 'Get', '(ss)', (
            cls.Interface, 'DaemonVersion'))
        yield Return(version)

    @Coroutine.from_generator_function
    def _sync(self):
        """Cache all device states."""
        object_pathes = yield self._proxy.call('EnumerateDevices', '()')
        yield AsyncList(map(self.update, object_pathes))
        yield Return()