PeerTable = Table[string, HashSet[PubSubPeer]]

func addPeer(table: var PeerTable; topic: string; peer: PubSubPeer): bool {.
    ...raises: [Defect], tags: [].}

func hasPeer(table: PeerTable; topic: string; peer: PubSubPeer): bool {.
    ...raises: [Defect], tags: [].}

proc hasPeerId(t: PeerTable; topic: string; peerId: PeerId): bool {.
    ...raises: [Defect], tags: [].}

func peers(table: PeerTable; topic: string): int {....raises: [Defect], tags: [].}

func removePeer(table: var PeerTable; topic: string; peer: PubSubPeer) {.
    ...raises: [Defect], tags: [].}