Thanks for point.
I changed this line multiple times.
```if (error) this._frontendClient.sendMessage(error);``` - wont to add FrontendClient as depends.
```if (error) return;``` - bad decision, but I probed this too.
```if (error) this.emit('discard');```
```if (error) this.emit('error');``` - I think will be great. I'll also modify ```session.js``` for send this error to frontend.