Returns chained list of top assets (photos and video) for commonized templates.

def get_top_assets(self):
        """
        Returns chained list of top assets (photos and video) for commonized templates.
        """
        imgs = self.articleimage_set.all()
        try:
            vids = self.videos.all()
        except AttributeError:
            # handles case where videos are not in installed apps
            # or otherwise unavailable
            vids = []
        return list(chain(imgs, vids))