How to use the subscriptions-transport-ws.SubscriptionServer.prototype function in subscriptions-transport-ws

socket.on("message", this.onMessage(connectionContext));
    };

    this.handler = connectionHandler.bind(this);
  }

  public close(): void {
    throw new Error("unexpected access");
  }

  public get server(): WebSocket.Server {
    throw new Error("unexpected access");
  }

  // @ts-ignore
  private loadExecutor = SubscriptionServer.prototype.loadExecutor;
  // @ts-ignore
  private unsubscribe = SubscriptionServer.prototype.unsubscribe;
  // @ts-ignore
  private onClose = SubscriptionServer.prototype.onClose;
  // @ts-ignore
  private onMessage = SubscriptionServer.prototype.onMessage;
  // @ts-ignore
  private sendKeepAlive = SubscriptionServer.prototype.sendKeepAlive;
  // @ts-ignore
  private sendMessage = SubscriptionServer.prototype.sendMessage;
  // @ts-ignore
  private sendError = SubscriptionServer.prototype.sendError;
}

this.handler = connectionHandler.bind(this);
  }

  public close(): void {
    throw new Error("unexpected access");
  }

  public get server(): WebSocket.Server {
    throw new Error("unexpected access");
  }

  // @ts-ignore
  private loadExecutor = SubscriptionServer.prototype.loadExecutor;
  // @ts-ignore
  private unsubscribe = SubscriptionServer.prototype.unsubscribe;
  // @ts-ignore
  private onClose = SubscriptionServer.prototype.onClose;
  // @ts-ignore
  private onMessage = SubscriptionServer.prototype.onMessage;
  // @ts-ignore
  private sendKeepAlive = SubscriptionServer.prototype.sendKeepAlive;
  // @ts-ignore
  private sendMessage = SubscriptionServer.prototype.sendMessage;
  // @ts-ignore
  private sendError = SubscriptionServer.prototype.sendError;
}