Well, I think if we pass ```event.target.result``` (or anything else in case of ```this.onMessageSendRequestCompleted.bind(this)```) here, we'll have to pass the same in every place where ```onMessageSendRequestCompleted``` is called to be consistent, but IMO it's over-complication since nobody uses it. Eventually we may want to pass something here, but I rather implement that only once needed. So my main rationale here is consistency vs brevity :)