Interface IPresenceManager

interface IPresenceManager {
    getUser(id: string): undefined | PresenceUser;
    getUsers(): PresenceUser[];
    isUserPresent(id: string): boolean;
    off(event: "join" | "leave", handler: (user: PresenceUser) => void): void;
    on(event: "join" | "leave", handler: (user: PresenceUser) => void): void;
}