def on_position(self, instance, value):
        labels = self._annotations_labels
        if not labels:
            return
        for label in labels:
            start = label.start
            duration = label.duration
            if start > value or (start + duration) < value:
                if label.parent:
                    label.parent.remove_widget(label)
            elif label.parent is None:
                self.container.add_widget(label)
dataset/ETHPy150Open kivy/kivy/kivy/uix/videoplayer.py/VideoPlayer.on_position/original