class WatchOneDim: movies: List[Movie] = field(metadata=config(shape=2))
class WatchMore: movies: List[List[Movie]] = field(metadata=config(shape=(2, 2)))
class Watch: movies: List[Movie] = field(metadata=config(shape=(2, )))
class WatchOptional: movies: List[Optional[Movie]] = field(metadata=config(shape=(2, )))
class Chess: num_moves: int next_move: Player board: List[Optional[Piece]] = field(metadata=config(shape=(64, )))