def frame_numbers(self):
        """All frame numbers existing in the :class:`OpenLABELStreamInfo`
        objects in this collection.
        """
        frame_numbers = []
        for info in self.infos:
            if info.frame_numbers:
                frame_numbers.extend(info.frame_numbers)
        return sorted(set(frame_numbers))
All frame numbers existing in the :class:`OpenLABELStreamInfo`
        objects in this collection.
        
fiftyone/utils/openlabel.py