scheduleSendingOfPendingMessages

Schedules an execution of PendingMessagesSenderWorker, which attempts to send all pending messages of this user.

When it's gonna to be executed may vary depending on the platform and/or implementation.

One of the criteria in order to attempt sending a message is that there's an established internet connection. So the scheduler may take this into consideration.

If the implementation is unable to schedule (due to platform limitations for example), it's OK to just don't do anything, ideally logging a warning about the lack of implementation.