def METHOD_NAME(self):
    self.loading = False
    self.loaded = True
    self.unloading = False
    self._video = VideoWrapper(filename=self.file)
    self._video.bind(on_load=self._check_duration,
                     on_play=self.on_play,
                     on_stop=self.on_stop)
    if isinstance(self._video, VideoNull):
        raise AssertionError("Kivy cannot load video {} because there is no provider.".format(self.file))
    self._call_callbacks()