chunks = foreign_filter(chunks, arg_or_GET('user'), 'user', User, 'username')
chunks = foreign_filter(chunks, arg_or_GET('stage'), 'stage', Chunk.tag_model, 'slug')
chunks = search_filter(chunks, arg_or_GET('title'), ['book__title', 'title'])
chunks = foreign_filter(chunks, arg_or_GET('user'), 'user', User, 'username')
chunks = foreign_filter(chunks, arg_or_GET('stage'), 'stage', Chunk.tag_model, 'slug')
chunks = search_filter(chunks, arg_or_GET('title'), ['book__title', 'title'])