How to use the @swim/warp.AuthRequest function in @swim/warp

protected onWebSocketOpen(): void {
    if (this.isConnected()) {
      const credentials = this.credentials();
      if (credentials.isDefined()) {
        const request = new AuthRequest(credentials);
        this.push(request);
      }
      this.onConnect();
      let envelope;
      while ((envelope = this._sendBuffer.shift()) && this.isConnected()) {
        this.push(envelope);
      }
      this.watchIdle();
    } else {
      this.close();
    }
  }