How to use the network.localUser function in network

private async authenticatePeer(peer: SimplePeer.Instance, peerId?: string) {
    const peerPublicKey = peerId ? sodium.from_hex(peerId) : undefined
    const userPublicKey = await mutualHandshake(peer, localUser().id, peerPublicKey)

    if (!userPublicKey) {
      const addr = `${(peer as any).remoteAddress}:${(peer as any).remotePort}`
      peer.destroy()
      throw new NetworkError(
        NetworkErrorCode.PeerAuthenticationFailure,
        `Failed to authenticate with peer [${addr}]`
      )
    }

    const userId = sodium.to_hex(userPublicKey)
    const netId = new NetUniqueId(userPublicKey)
    const conn = new RTCPeerConn(netId, peer)

    console.debug(`Authenticated peer ${userId}`, conn)
    this.emit('connection', conn)

private async createSession() {
    let client

    try {
      client = await this.getClient()
    } catch {
      throw new NetworkError(NetworkErrorCode.SignalServerConnectionFailure)
    }

    try {
      await client.createRoom({
        publicKey: localUser().id.publicKey,
        privateKey: localUser().id.privateKey!
      })
    } catch (e) {
      console.error(e)
      throw new NetworkError(
        NetworkErrorCode.SignalServerConnectionFailure,
        'Failed to create room'
      )
    }

    client.on('peer', this.authenticatePeer)
    client.on('close', this.serverConnectionClosed)

    this.sessionClient = client
    this.intervalId = setInterval(this.keepAlive, KEEP_ALIVE_INTERVAL) as any

    console.debug('Created signal client session')

private async createSession() {
    let client

    try {
      client = await this.getClient()
    } catch {
      throw new NetworkError(NetworkErrorCode.SignalServerConnectionFailure)
    }

    try {
      await client.createRoom({
        publicKey: localUser().id.publicKey,
        privateKey: localUser().id.privateKey!
      })
    } catch (e) {
      console.error(e)
      throw new NetworkError(
        NetworkErrorCode.SignalServerConnectionFailure,
        'Failed to create room'
      )
    }

    client.on('peer', this.authenticatePeer)
    client.on('close', this.serverConnectionClosed)

    this.sessionClient = client
    this.intervalId = setInterval(this.keepAlive, KEEP_ALIVE_INTERVAL) as any

(state: IAppState): IConnectedProps => ({
      hasPlaybackPermissions: hasPlaybackPermissions(state, localUser()),
      currentMedia: getCurrentMedia(state),
      mediaQueue: getMediaQueue(state),
      mediaQueueLocked: state.mediaPlayer.queueLocked
    })
  )(_MediaList)