How to use the lnd-grpc function in lnd-grpc

connect(options) {
    if (this.grpc && this.grpc.state !== 'ready') {
      throw new Error('Can not connect (already connected)')
    }

    this.options = options

    // Create a new grpc instance using settings from init options.
    const grpcOptions = this.getConnectionSettings()
    this.grpc = new LndGrpc(grpcOptions)

    // Set up service accessors.
    this.services = this.grpc.services

    // Inject helper methods.
    Object.assign(this.services.Lightning, lightningMethods)
    Object.assign(this.services.Lightning, lightningSubscriptions)
    // Setup gRPC event handlers.
    this.grpc.on('locked', () => {
      this.emit(GRPC_WALLET_UNLOCKER_SERVICE_ACTIVE)
    })
    this.grpc.on('active', () => {
      this.emit(GRPC_LIGHTNING_SERVICE_ACTIVE)
      this.subscribeAll()
    })