from typing import Any, Dict, Set class SubscriberHandler: def __init__(self) -> None: self.stream_info = dict() # type: Dict[int, Set[int]] def set_info(self, stream_id: int, users: Set[int]) -> None: self.stream_info[stream_id] = users def get_users(self, stream_id: int) -> Set[int]: users = self.stream_info[stream_id] return users