@classmethod
def remove_room_member(cls, room_id: int, user_id: int) ->None:
    """Remove a room member who left stored in a room.

        :param room_id: The room's ID the user left from
        :type room_id: int
        :param user_id: The ID of the user who left
        :type user_id: int
        """
    member = cls.rooms[room_id].members[user_id]
    cls.rooms[room_id].members.pop(user_id)
    if cls.member_changes['left'].get(room_id) is None:
        cls.member_changes['left'][room_id] = cls.rooms[room_id]
    cls.member_changes['left'][room_id]._members_left[user_id] = member
